Midair collisions throughout aviation history have brought some of the worst tragedies in the sky. But they've also left important lessons.

Everyone aboard a plane that collided with an Army helicopter near Washington, D.C., are feared dead, which would make it the ...

Fatal crashes of commercial aircraft in the U.S. have become a rarity. The last was in 2009 near Buffalo, New York.

The fatal D.C. plane crash has renewed focus on the recent history of crashes and near misses in U.S. airspace.