Left 4 Dead Wiki
The Sewer Official.jpg
Chapter 3
The Sewer
Campaign No Mercy
No Mercy Chapter Chronology
Chapter 2
The Subway
Chapter 3
The Sewer
Chapter 4
The Hospital
"This is not going to be sanitary..."
"Hospital's on the other side of the waterworks."

The Sewer is the third chapter of the first campaign, No Mercy.

The Survivors begin in a safe room at the Pawn Shop. The usual Tier 1 weapons, first-aid kits, an extra pistol, and an ammo stash are provided.

This chapter has the Survivors fighting an infected horde before entering a warehouse and the Fairfield sewer system to exit via a manhole in front of Mercy Hospital.


Also see: Tactics

All campaign walkthroughs are done on Normal difficulty in single player, and are meant to give tips on what to do and generally point out things that might otherwise be missed.

There are, of course, a few key things to always remember:

  • Stop, look, and listen.
    • Being observant might alert you to something nasty ahead of time, like a Witch, Special Infected or Tank, and allow you to prepare yourself.
  • Teamwork.
    • This cannot be stressed enough. Left 4 Dead is supposed to be a cooperative game. Communicate with your teammates, if you're playing with others, or if you're by yourself with the AI, point out things they might otherwise miss. In all cases, watch out for each other and take care of each other. You are not going to survive the zombie apocalypse by yourself.
  • Be ready for anything.
  • Don't panic.

Infected prowl through the buildings, and there are many places for Special Infected to lurk, so always keep your wits about you. Witches are all but guaranteed to spawn here, though can usually be avoided as long as you spot them first. Tanks will frequently appear in open areas, but don't count on it.


When starting from this chapter, all four Survivors will grab a Submachine Gun.

When Tier 2 weapons are found:

Otherwise, they will keep the weapons they had from the last chapter. (See The Subway for a list of weapons they will grab there).

If you're starting on this chapter, make sure everybody grabs a first aid kit and a weapon. They are entirely necessary to everyone's survival. If you started in an earlier chapter, heal up if you need to and take what you can. As there are lots of open areas on this level, the submachine gun is a good option, though with luck, Tier 2 weapons will become available shortly.

The first area of this map is relatively small. After opening the safe-house door you can turn either left or right. Going left brings you straight to the back door of a Burger Tank restaurant. Turning right takes a longer route to the Burger Tank but gives you a chance to explore a two-vehicle garage, a parked truck and various alcoves for Pain Pills and Grenades, along with a possible place for a Chainsaw and special ammo in L4D2. Regardless of the route taken, Smokers and Boomers are a real threat. If you move slowly the AI Director will send a Horde at you.

Proceed through the Burger Tank, mopping up loitering infected as you go. The diner front windows allow you to snipe all visible enemies within a large courtyard area. Take your time, this is one of the few spaces where you will not be hit by a hurry-up horde. In L4D2, stay on the lookout for a Fallen Survivor in this area, if you haven't killed him already. Pay attention to rooftops and dark corners for Smokers and Hunters and practice stealth and evasion if a Witch is present. Be careful not to shoot the gas station pumps because this will cause the facility to explode prematurely, and you should keep this destructive opportunity in reserve for the battle which lies ahead..

  • This is one of the four most likely times for a Tank to appear (especially in versus mode). If you hear one coming, be sure to stay in the open area right outside the diner. This offers the most maneuvering room, so the Survivors can employ anti-Tank strategies.

The gas station exploding.

Note that prior to blowing the gas station, it is possible to access a series of rooms overlooking the scene containing supplies and Tier 2 weapons by jumping up on a stack of cable drums (look for the blue dumpster that provides a directional marker). Alternatively these rooms can be reached after the gas station has been destroyed by using the resultant rubble pile. With the release of The Sacrifice, melee weapons can be used in the No Mercy campaign in Left 4 Dead 2. Because of this, players with melee weapons must take care when near the gas station since a misdirected melee swing can make the gas station explode on top of them.

To the left of the gas station is a scissor lift. A Survivor will instruct you to get on the lift. Activating this device triggers this campaign's second Crescendo Event. A sizeable horde lasting some minutes will attack from various directions as the lift moves noisily upwards to the rooftop of a nearby warehouse. Provided the team is quick to take down any Smoker, it is possible to defeat the attack by holding out on top of the lift. Alternatively the team can form a defensive huddle in the corner of the roof next to the lift.

Ranged weapons are particularly effective because the infected will seen at a distance and approach from a limited number of predictable directions.

If you are pulled from the raised lift or need to ascend or descend it for any reason, it comes equipped with a ladder on the gas station side.

When the moment is right, firing at the gas station will instantly kill any nearby Infected and start a blaze to destroy any others who attempt to attack from that direction.

Once on the rooftop, proceed along to the large-windowed room. If you are still fighting the horde when you get here, don't jump into the hole. Throw a Molotov down into the hole to burn any incoming Infected and shoot any that try to come in through the window. Once the horde has been dealt with, you can drop down the hole into another room with a first-aid cabinet, an ammo supply, and sometimes Tier 2 weapons. When ready to proceed, either head down the stairs to the warehouse floor or into a room down the hall which has a view of the warehouse (and sometimes a Pipe bomb). One of these rooms has the chance to spawn Boomer Bile, the only naturally spawning canister in the entire campaign. Grab it.

Note: Under the overhanging roof of the warehouse, in the back left corner, there is a metal door. This door can normally be opened by a button on the inside of the building, or by a Tank crashing through it. If the Tank breaks the door open before you start the Crescendo Event, feel free to punish him for his mistake. Before a recent patch, it was possible to break the door using melee attacks, effectively allowing you to bypass the Crescendo Event. Hit the door roughly in the center until you hear the same sound that is played when you successfully melee shove an Infected. After hitting it for a while, it does break. Alternatively, if one has a spare pipe bomb at this point, or even a propane tank, they can throw it near the door (and shoot it, in the case of the propane tank) and severely weaken the door, if not completely break it.

Be sure to heal up if need be before entering the warehouse, as this is a notorious ambush spot. Proceed quickly, and stay close together. Smokers frequently hide on the catwalks, while Hunters and Boomers will dwell among the dark aisles. Don't give them a chance to stop your advance. If they are encountered, punch a Smoker's victim to release them from its hold, and destroy Hunters as quickly as possible. In the event of Boomer vomit, quickly move to a nearby wall, and move as soon as you can see again.

  • This also happens to be the second of the four likely spots for a Tank to appear. If he appears, don't wander too far from the first part of the room, since the Smokers, Hunters, and Boomers are just itching to add to the chaos. Instead, prepare for this battle by hitting the button to open the door before entering. If a Tank appears, retreat back outside, where it may be more easily disposed of.

Once out of the warehouse, move down the alley and follow the hallway until you get to a stairwell. At the bottom lies a generator room, with a manhole at the other end. Since the generators provide lots of cover for Special Infected, make sure to check behind these as you go. You have two options to get to the sewers.

  1. Get to the manhole on the other side of the room, and drop down onto a wooden plank above the sewers.
  2. In the middle of the right wall, there is an often-overlooked room. This room contains another manhole into the sewers, and sometimes a Pipe bomb or a Molotov. However, Special Infected are able to crawl out of this particular manhole, so watch for that.
  • The generator room is the third location a Tank will often appear. If you have not encountered one yet, you will here. Either immediately leave the confined spaces of the stairwell, or retreat back the way you came while shooting. Molotovs are dangerous in the limited spaces this area contains.

If you dropped onto the plank, there will be a "T" intersection. Take the right-hand turn, and then make a left. If you took the other route, proceed forward to an intersection, and then continue forward. This will place both groups traveling along the same path.

While the sewers themselves are rather wide-open, there are many small passages off of them. Special Infected love ambushing unsuspecting Survivors out of them. Avoid this by keeping your distance from them, and staying close together. Also, in L4D2, keep an eye out for "Mud" Men. The path to take is lit up by overhead lights, so stay out of the dark areas to proceed. Eventually, an open door will appear along one of the walls. Pass through it into the room beyond (closing the door behind you as always). There will usually be an ammo supply on the ground, and there is a chance that grenades, pain pills, Tier 2 weapons, or even a health pack will be here. Enter the nearby tunnel to proceed.

After the tunnel turns right, move forward until it opens back up into the sewers. There is an offshoot to the left where Special Infected will hide, so be wary of that when you pass it. Once out of the tunnel, follow the same lighting rule to get to a ladder. This ladder will take you out of the sewers. Before progressing, now is a good time to heal, pop some Pills and check ammo.

A surefire way of getting safely out of the sewer is to have one player switch off their flashlight and use a pipe bomb. This person takes point and climbs the ladder followed rapidly by the rest of the team. The moment the point player reaches the surface, the Pipe Bomb is hurled in the direction of the hospital (the way the ladder is facing) and that person backpedals to put their back against the wall of the building nearby, covering the rest of the team as they leave the sewer and link up again. From there it is a simple fire and movement drill to reach the hospital entrance. Note that Special Infected love this area and a Witch will often spawn somewhere inconvenient. Alternatively if someone has a Molotov, they should carefully throw it so that it lands just outside the sewer exit, burning any would-be ambushers. Or, if you have the Bile from earlier, throw it at a precise angle from the sewers to distract all the Common Infected just waiting for your arrival. Failing that, make sure the team leaves in shifts of two so there will be someone to help out. Backing up to the aforementioned building wall will channel enemies and greatly improve the Survivor's odds.

  • This stretch of the sewer is the last of the common areas a Tank will spawn. Move to an intersection where there is slightly more room to move. If in the second area, do not face him on the street. Cars litter the road, and are a surefire way of someone getting incapacitated or killed. He will follow you into the sewers, so take him there rather than put everyone at risk up above.

Everyone out? Good! The hospital is in sight. While it may be tempting to bolt straight to the safe-room, many teams have died by doing that. Plus, this is where CEDA workers may start spawning, with their Bile, and this is even another area where Bile can spawn naturally. Another Fallen Survivor can spawn as well, so keep an eye out. Smokers will dwell above the entrance, while Hunters and Boomers will attempt one last attack inside. Use the ambulance just outside the doors as a waypoint, and quickly check inside it. A healing item will often spawn in here, which will be valuable when you proceed. If you are playing in Versus, the item won't be valuable, but a Special Infected may choose to hide in there. Either way, move at a swift but regulated pace using fire and movement to enter the hospital, and jump the counter to enter the safe room. If time permits, a consulting room to the left may give up a supply item like a Pipe Bomb.

Left 4 Dead 2 Version[]

From the Survivors' perspective, this map remains mostly unchanged from the Left 4 Dead version. Additional climbing points have been added for the Infected in various parts of the map, most notably in the gas station crescendo area.



Remember all those devious places the Special Infected like to lurk? Human-controlled Infected will ruthlessly use these to slaughter your entire team. The best way to counter them is to deny them a good chance to do so. Gear up quickly, as well as the second pistol which now presents itself, and rush to that diner. The less time you spend here, the better.

If you're feeling lucky, go through the doorway to your right. This will lead you through a storage area, and on the other side is a small garage area. This area may hold Tier 2 weapons, and it's possible that other useful items (such as pills and various grenades) will spawn in the storage area. If you do this, move fast. The longer you're out here, the longer the Infected have to mess with you. As long as everyone moves with a buddy, everything should be fine. Once you've gotten your fill, run down the alley, turn left, and go inside of the restaurant.

Stick together! Yes, yes, you already know, but don't even split up into two groups of two. The large amount of hiding areas makes this a dangerous level to get separated in.

Always search the room above the blue dumpster and the garage at the beginning. You don't have the advantage of keeping Tier 2 weapons from the last section.

Be especially careful of shooting when you see a Special Infected and hear a Witch; they like to conceal the Witch from your initial line of sight, and you probably know very well what happens when you shoot at her.

Once you're in the room with the hole—assuming you took that route—hurry up and drop down. If a Smoker drags somebody out from the window, it's almost certainly a kill. After entering the room below, which has ammo and a First-Aid Station, be sure to stay away from the windows. They can still pull you out, and needless to say, that's not much fun, either.

A Hunter taking out Francis on the one way drop

Have the last person run backwards down the dark hallway after the warehouse. This way, he can protect himself from any Infected planning a flanking maneuver.

Always enter the room on the right wall of the generator room. It is much easier to protect against lurking Special Infected in there. Once you've entered the Sewers, be especially wary of the tunnels. They're a great place for Infected to hide in, and getting ambushed due to one's carelessness when running by the tunnels isn't very nice. Make your way to the last manhole of the sewers. When there, try your hardest not to let anyone go up alone; this is a crucial choking point for the Infected, and they can pull you away or pin you down one by one as you get off the ladder. Get everyone up, one way or another, and make a run for the hospital.

The Infected[]

See also: The Boomer, The Hunter, The Smoker, The Tank

The Survivors are half-way to the hospital; half-way to escaping. Don't let them. Though they may have stubbornly resisted your efforts in the past, you will hinder them from getting away... just be sure to team up on them, and they won't stand a chance.

Overall Tips

  • Any survivors that choose to run ahead of or fall behind their teammates will be much easier to seriously damage and kill. The farther away they are from their teammates, the more likely they are to be incapacitated or die before their teammates can reach them.
  • The Survivors all have outlines around them, showing their status and location. Green means they're healthy. Yellow means they're hurt. Red means they're low on health. Purple means they've been covered in Boomer bile. You can probably discern which to seek out first if possible.
  • Think like a Survivor. When you play as one, when are the worst times that something could come at you? Exploit that knowledge.
  • Teamwork, as aforementioned. Has a Boomer gotten their bile all over the Survivors? Jump one of them or a clean one. They can't see their teammates' aura until they're clean...and by then, it might be too late.
  • As much as teamwork is a strength for you and your enemies, a lack of it will be their downfall. If you can focus all of your energy on killing one of the Survivors, the rest will be that much easier to take down. Not only will they have one less gun, but they will have three Survivors to your three incapacitating Infected.


  • Pre-Diner ambush ― The Smoker waits on the rooftops, the Boomer in the alley to the left of the diner, and the Hunters in the alley to the right. As soon as they come in sight, the Boomer vomits over as many as possible. Immediately afterwards, the Smoker and the Hunters grab three of the Survivors, being sure to get any not covered with bile. If done right, this can be a game-changing maneuver, or even outright kill the entire team with some luck.
  • Three-Survivor pin ― Obviously, it is possible for three Survivors to be incapacitated at once by using the Smoker and two Hunters. Because the Tank frequently spawns early in the level, it is possible for him to concentrate on one Survivor enough to kill it, though it is risky. To help with this, the Boomer should also target this Survivor, vomiting and then clawing it. Once they are down a member, set up an ambush somewhere dark, such as the warehouse, and grab all three of them. They won't be able to retaliate if done quickly.
  • Witch Ambush ― Though this is a very recognized technique, the Sewer is arguably the best stage for this trick if a Witch spawns in the depths of the sewer. The dark lighting allows a Special Infected to block out the Witches glowing red outline by crouching in front of her. The darkness can also block out the Special Infected themselves, especially if they are a Hunter. When a Survivor sees you, they'll shoot you, and alert the Witch. When another Survivor comes to help the incapacitated, you can pounce or rope them. A Boomer will have already exploded, and hopefully splashed onto the Survivor, pretty much dooming them, and earning you points. When performing this trick, it's good to have another special Infected, preferably a Smoker, to grab a third Survivor.

The Boomer: There is plenty of opportunity to wreak havoc among this level. Try dropping off a roof into the middle of the Survivors for a surprise, or vomit down upon them, letting gravity extend your reach. Hide in areas they will have to pass through to make the arrival of a horde inevitable. Stay out of any open areas where you will be vulnerable, and spawn in an area in front of the Hunters. Whenever a Tank is attacking, take advantage of the situation and catch as many Survivors as possible in your bile.

A Hunter waiting atop the sewer exit

The Hunter: This map is more difficult for you than for the other Special Infected. Team up with another Hunter to maximize your effectiveness. Climb to a high place before pouncing in order to increase the bonus damage you do, such as the roof opposite the diner. When the Survivors activate the lift, wait at the top, and then pounce on one. Because the Hunter pushes back his victim, you are likely to knock the Survivor off the lift, giving you a bit more time while his buddies figure out where he went. When the Tank appears, jump on healthy Survivors he is going after. Even if you die, you allow the Tank to catch up and tear that Survivor apart. The one way drops into the sewers are another perfect place to pick of a straggler for good, with the others unable to climb back up you can almost certainly kill that Survivor. Another good tactic is to wait at the top of the red ladder exiting the sewers and pounce the first one up, sending them crashing back down the hole to the base, delaying the team enough for a Boomer to wreak havoc with a vomit attack.

The Smoker: This area is made for you. At the beginning, climb to the top of the rooftops as quickly as possible. If you climb above the safe-house, you have a good line of sight to yank a Survivor out of the diner. If possible, always try to be behind the Survivors, since pulling someone backwards in the level is more effective than pulling someone forwards. Pulling a Survivor back down the hall after the warehouse is a particularly good example. If you can manage it, try to strangle a Survivor who just went down the manhole. At the hospital, either grab the last Survivor to climb the ladder, pulling them back down into the sewers, or the last one into the hospital. When the Tank is around, be sure to target healthy Survivors the Tank is not currently chasing. Also, you can get onto the fire escape near the climbable building by the safe room; people do not expect you to be up there. If the Survivors don't shoot the gas station at once, another risky strategy would be to hide behind one of the gas pumps in the gas station. Once the Survivor move close enough, grab one of them. If they shoot you, there's a chance they'll shoot the gas pump and kill you in the explosion, along with your victim. If you're lucky, this could even result to death of all the Survivors if they are close enough.

The Jockey: Initially, you seem to have little use in the early parts of this chapter, however, you can hide behind various shelfs and alleyways to get in damage. Additionally, steering survivors into the gas station may cause some unfortunate results for their team. When a survivor drops down the hole during the Crescendo Event, try and steer them back into gas station area to cost survivors time and health. The large amount of closets here can work to your advantage as well. Try and work with Spitters, Boomers, and any Witches you see to cause chaos, especially in the many narrow corridors of this chapter. Due to your relatively speedy leap, you can trap a survivor above the entrance to the sewer! In the sewers themselves, try and take survivors for a ride through the dark and twisted side passages.

The Tank: First off, be sure not to break down the metal door, or you will allow the Survivors to skip the Crescendo Event. When playing as the Tank, be careful to avoid fire, this will cause your health to go down significantly until you die. Go after the weak Survivors first, pummeling them until they can't get up. Since the Survivors are likely to be faster than you, you need a way to catch them. If you ignore the first downed Survivor for a few seconds, somebody will inevitably try to get them up, during which time they can't move. Use that time to run up and put them in the first chum's shoes. There are forklifts and freight dollies near the Crescendo Event, as well as a car and dumpsters in the alley you can punch into the Survivors to incapacitate them. Even after such, you are still quite the threat. When the Survivors open the manhole cover to get out of the Sewers, be sure to have something to shove down there. If done right, it will incapacitate all survivors on the ladder and extremely hinder their progress. One such example of an effective use of this tactic can be seen in one of the YouTuber Criken2's "Funny Moments of Getting Owned", in which a dumpster was shoved down the manhole and seriously hindered all progress, blocking the ladder. Keep in mind, however, that punched objects such as dumpsters and cars will vanish after a minute, regardless of whether they receive multiple punches or not.


See also: Survival Mode

The Survivors activated the lift and raised themselves up. Their elevated height did not shield them from the unstoppable waves of Infected. How long can the Survivors hold out?

Overall Tips

  • Teamwork is essential to long-term survival.
  • In this mode, most of the popular choke points, closets and easily defensible corners are removed. Even if you find one that has not been removed, it is not recommended that you fight from there as The Tank will quickly defeat you when he arrives.
  • You have an infinite amount of time to prepare. Use this to your advantage. Take as much time as you can to set up gas cans, propane tanks, oxygen tanks and to find a good place to fight from.
  • When searching for a place to fight from, remember that you need a location that not only limits where the horde attacks from, but also gives you a fair chance against the Tank. You either need to be able to fall back and deal with the Tank easily, or have a good enough vantage point to kill him before he can get too close.
  • Ammunition is a problem. Unless you are being overrun with Infected or fighting a Tank, try to use your pistols as much as possible. Conserving ammunition should be a priority, as trying to get more during a horde attack can often be fatal. When you do head out for ammunition, remember to take at least one teammate with you.

Lift Method

Have the team ascend the lift, activate it to bring it up level with the sloping roof and engage the horde on an ad hoc basis. Since the attackers have to traverse a wide area of open ground and they follow two main lines of attack (climbing the ladder on the lift and onto the sloping roof via the trucks in the yard below), they are relatively easy to defeat (in fact, their behavior is sometimes quite puzzling because those charging towards the team across the sloping roof may often jump to their deaths just before they attain a threat range). Note that horde members not only spawn in the yard below, but also from the roof to the right of the lift, so a weather eye needs to be kept on this part of the stage. Have one player cover the head of the ladder on the lift, a shotgunner looks to the sloping roof and two with rifles ply their fire opportunistically. The only risk with this position concerns Smokers, who can pop up on the roof to the right, but fortunately they only drag players a short distance and the angle on the shot from the top of the lift makes it easy to take these unimaginative creatures out. A good idea is to wait until a section of the horde is in the right place in the yard below and then have one player fire at the gas station, thus blowing it up and wreaking thereon great havoc and execution. The benefits of elevation and lack of obstructions make it easy to bring down most Boomers and Tanks at comfortable ranges. Do not make the mistake of holding this position at all costs in the face of a Tank assault; instead, exercise good tactical judgement and reposition the team out on the sloping roof as needs dictate.

Rooftop Corner Method

Once the lift has risen, you will have a sloping rooftop to your right featuring a right-angled corner where this roof meets the warehouse wall. This corner is an effective position from which to fend off the Infected. Two people cover the lift and gun down attackers who have climbed its steps, whilst the others cover the sloping rooftop. The Common Infected will mostly charge in thin lines making them relatively easy to defeat. This method deals with Boomers, Smokers, Hunters and Tanks effectively since they find it difficult to get to players clustered under the roof overhang. Keep in mind that this method will only work effectively if all of the Survivors keep themselves bunched together in the corner.
Provided the Survivors keep themselves in the corner, the Boomer will spawn on the rooftop of the building facing the corner and can be handled with little difficulty since he normally self-eliminates by jumping down, hitting the ground and exploding. However, if one or more Survivors leave the corner, the Boomer may either spawn on the ground below and ascend the ladder (making him an easy target), or spawn on the rooftop above and drop down onto the sloping roof. In any event, expect at least one Survivor to be at risk of receiving a face full of bile.
Hunters are forced to ascend the ladder, as they believe that there is no other good location from whence to mount a pounce. This gives the Survivors ample time to kill him as not only does it take a few seconds for them to come off the ladder at the top, but they hesitate to pounce once they are up on the lift platform. Hunters rarely attack from across the rooftop, and even if they do, players have time enough to spot them and engage them before they can get into pouncing range.
Provided players are close enough to the corner, there is no risk of Smokers dragging anyone off the sloping roof down into the courtyard below. Instead they will appear on the roof above and drag people against its supporting wall. At most, individuals will taken only a few meters away from their team mates so they can be easily freed and the rooftop Smoker eliminated. Like Hunters, Smokers may also attempt to climb the ladder to get to the Survivors but this is rare.
With the benefits of elevation and lack of obstructions, players can spot and engage the Tank from long range and with plenty of time to bring him to submission. The Tank will generally climb on top of a truck and then mount the sloping roof so that he can make a final run across the roof towards the Survivors. However, he may occasionally avoid the truck and climb the lift's ladder, in which event the team will have to fall back along the sloping roof in order to open the range and keep themselves out of immediate danger.

Second Floor Method

The first room on the second floor that you enter via the windows on the rooftop is a fairly easy position to defend. This is a popular and effective place to defend mostly because in this room, there are a total of five Pipe bombs and three Molotovs. From the back of the room, there is a corridor-like passage. Facing away from Mercy Hospital, two Survivors can shoot down this passage and restrict movement of the oncoming hordes. The other two can face towards the other direction that the Infected can attack from and defend there. If things get too much to handle at the front, one of the Survivors guarding the second passage can move over to help defend the first one.
This tactic deals well with Smokers, as it is too close for them to be effective. It also deals well with Hunters, as they are heard long before they are seen and infrequently, they don't even reach your position. The downside to this tactic is the Boomer. However, as long as the team stays fairly far back and shoots him before he can do anything, they shouldn't have a problem. The Tank is dealt with by either fighting him whilst maneuvering around and around the passages, or by using one of the three Molotovs to set him alight and then avoid him until he dies.

Behind the Scenes[]

In earlier footage, it seems that the players had to get to the roof by going through the building to the left of the gas station, not by using a lift.

An early picture of the front of the Hospital shows that there was to an advertising billboard to the left of the hospital at one time.


  • The gas station explosion instantly kills anything standing in the center of the station, including Tanks and Witches.
  • The Sewers is one of the most modified maps in the history of Left 4 Dead. Several older versions had players go from warehouse to warehouse, through a gas station market, and even up a truck to get into the main sewer entrance.
  • If you look closely when you get to the warehouse, you can see a white helicopter land on the roof of the hospital, (and if you're patient enough, it going back and repeating) possibly hinting there were other Survivors that were in the city and contacted the pilot. If you look closely at the chopper, it has a different color than the chopper that is going to rescue you.

Warehouse Door.JPG

  • It used to be possible for the Survivors to break down the metal door to the warehouse and bypass the second Crescendo Event. Although this is not a bug, it is most likely a placement mistake on Valve's part. An attempt was made to fix this door, but it was only half successful. About 50% of the time, the door can still be broken with enough hitting. Of course, it takes a long time to break the door by shoving, and with the uncertainty as to whether the door might be breakable for you, your team will have either wasted too much time hitting and realize that this time around it is solid, or they'll get tired quickly even if the door is breakable. Either way, it's rarely ever attempted in versus, and still often skipped in Campaign mode. CAUTION: Sometimes when breaking this metal door to the warehouse, a horde may or may not be attracted.
    • In Left 4 Dead 2, the door was able to be destroyed by a single strike from a melee weapon, allowing Survivors to bypass the crescendo event entirely. After several patches, the door can no longer be broken with melee weapons, but a Grenade Launcher can still break down the door.
  • The warehouse door can be opened from the inside, making it easy to go back if you missed anything (such as grenades or pills) after the Crescendo.
  • The restaurant that the Survivors go through at the beginning of the chapter is called "Burger Tank" and the warehouse that they have to go through is a Hersch Shipping Company warehouse.
  • The convenience store at the gas station is named, Pump 'N' Run, which is a reference to the game's shooting and running style of gameplay.
  • Standing near the gas station when it explodes and surviving (right after spawning in Survival Round) will make the Survivor temporarily deaf.
  • In the Left 4 Dead 2 version of this chapter, laser sights and ammunition upgrades spawn more often than any of the other chapters of the campaign. These assets typically spawn in the small sewer side passages.
  • Despite being able to sprint through the sewer water in the original version, the Left 4 Dead 2 version of this map incorporates the water speed restriction featured in Swamp Fever and Hard Rain.
  • The Left 4 Dead 2 version of this map allows the gaspumps to detonate even with a strike or blunt from a melee weapon.
    • If The Charger charges into the gas pump it will be oddly moved but not detonated.
Left 4 Dead Left 4 Dead 2
L4d no mercy.jpg
No Mercy
The Apartments / The Subway / The Sewer / The Hospital / Rooftop Finale Price chopper.jpg
Dead Center
The Hotel / The Streets / The Mall / The Atrium
L4d achievement survive garage.png
Crash Course
The Alleys / The Truck Depot Finale Torch-Bearer.gif
The Passing
The Riverbank / The Underground / The Port
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Death Toll
The Turnpike / The Drains / The Church / The Town / Boathouse Finale Midnight rider.jpg
Dark Carnival
The Highway / The Fairgrounds / The Coaster / The Barns / The Concert
L4d dead air.jpg
Dead Air
The Greenhouse / The Crane / The Construction Site / The Terminal / Runway Finale Ragin cajun.jpg
Swamp Fever
Plank Country / The Swamp / Shanty Town / The Plantation
L4d blood harvest.jpg
Blood Harvest
The Woods / The Tunnel / The Bridge / The Train Station / Farmhouse Finale Weatherman.jpg
Hard Rain
The Milltown / The Sugar Mill / Mill Escape / Return To Town / Town Escape
Supreme sacrifice.png
The Sacrifice
The Docks / The Barge / Port Finale Bridge burner.jpg
The Parish
The Waterfront / The Park / The Cemetery / The Quarter / The Bridge
L4D last stand.jpg
The Last Stand
The Lighthouse Streamcrosser.jpg
Cold Stream
Alpine Creek / South Pine Stream / Memorial Bridge / Cut-throat Creek
L4d outbreak.jpg
Dam It
Orchard / Campground / Dam Achievement Still Standing.png
The Last Stand
The Junkyard / Lighthouse Finale