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.

A jet carrying 60 passengers and four crew members collided Wednesday with an Army helicopter while landing at Ronald Reagan National Airport near Washington, prompting a large search-and-rescue operation in the nearby Potomac River.

An Army Black Hawk helicopter collided midair with an American Airlines flight from Wichita, Kansas, at Reagan National Airport on Wednesday.

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

First responders are searching the Potomac River after an aircraft collided with a military helicopter mid-air Wednesday night near Washington D.C. According to the FAA, a PSA Airlines jet collided in the air with a military helicopter while headed towards Runway 33 at Ronald Reagan Washington National Airport.

A PSA Airlines Bombardier CRJ700 regional jet collided with a Sikorsky H-60 helicopter, the FAA said. Reagan National Airport has grounded all flights.