Divers return to the Potomac River as part of the recovery after the United States’ deadliest aviation disaster in almost a quarter century

Altitude, staffing and communication are some of the aspects that investigators will evaluate. The crash killed all 67 people on board the two aircraft, the worst U.S. airline crash since 2001.How an Army Black Hawk helicopter collided with American Airlines jetliner in a deadly crash over the Potomac River Wednesday night is still unknown,

Sixty-seven people died in a collision between a Bombardier CRJ700 regional jet operated by PSA Airlines and a military Black Hawk helicopter.