On Wednesday night, an American Airlines passenger plane collided with an Army Black Hawk helicopter near the Reagan National Airport in Washington DC. It is the deadliest U.S. air disaster in the last two decades. Some of the people who died in the crash were a groom-to-be pilot, a Harvard-trained civil-rights attorney, and figure-skating champions. 41 bodies have been recovered so farm and as the research continues, authorities are investigating black-box data to determine what caused the deadly crash.