Understaffed and overworked air traffic control crews have long been an issue at Ronald Reagan Washington National Airport, lawmakers say — another potential cause of the midair collision between a commercial jet and military helicopter over the Potomac River that killed 67 people Wednesday night in the nation’s deadliest air crash since 2001.

An American Airlines plane carrying 60 passengers and four crew members collided with an Army Black Hawk helicopter outside Reagan National Airport near Washington, D.C. Wednesday night. A D.C. fire official said Thursday that “we don't think there are any survivors from this accident" and "we are switching from a rescue operation to a recovery operation.

The deadly mid-air collision over Washington, D.C., has reignited concerns over air traffic congestion and safety risks at Ronald Reagan Washington National Airport, a tightly packed aviation hub that shares airspace with military and government flights.

A midair collision between an Army helicopter and a passenger jet killed all 67 people aboard the two aircraft, officials said, as they search for answers in the nation's deadliest aviation disaster in nearly 25 years.

An airplane collided with a helicopter while trying to land at the Ronald Reagan Washington National Airport on Wednesday night, officials said.