Metro International Airport

Metro International Airport is the setting for the last three levels, mainly featured in the fourth level(third level features the entrance; final level features the runway) in the campaign Dead Air.

History
Before the Infection, the airport was one of the many ways out of Newburg, but as the Infection started to spread throughout the city, the airport was shut down and converted for evacuation of citizens by CEDA and Newburg police. By the time the Survivors arrived to be evacuated, the airport was already bombed by the military and completely overrun. The Survivors arrived just in time to watch a plane seemingly try to land, but the pilot appears to have become Infected or died and promptly crashed on the runway, causing flaming wreckage and debris to hurtle towards the unsuspecting Survivors.

Having seen what appeared to be their savior die in a most unsavory manner, the Survivors escape the airport in a Lockheed C-130 Hercules of Korean design.

Current Status
Metro International Airport is overrun and has been largely destroyed by multiple plane crashes, but it is possible that the airport (along with the rest of the city) may have been bombed. This is supported by the fact that the military were seen bombing Infected in Left 4 Dead 2 and that the Survivors will occasionally comment that the airport was bombed. Some Infected inevitably got through during the panic. The military may have known that it was crawling with infected, so they decided to bomb it. If so, other survivors can't use this anymore, since it was bombed and still has infected. Probably, there is absolutely no hope, so they bombed it. Or also a note that it was a way to prevent people to fly on an airplane, immune or not, but they didn't know that they were carriers, probably a way to prevent the infection from spreading further into the world.