What happened inside the Army Black Hawk helicopter in the moments before the fatal crash is key to unraveling the disaster as plane collision investigations begin.
More details are coming out about the victims of this week's devastating mid-air collision between a passenger plane and an Army helicopter near Washington, D.C., killing 67 people.
More than 700 planes had already taken off and landed at Reagan National Airport on Wednesday when American Airlines flight 5342 approached it through one of the nation’s most congested air corridors.