Investigators trying to determine what caused last week’s deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, briefed lawmakers Thursday on what they’ve learned after combing through data from both aircraft and air traffic control.

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.

All of the "major" pieces of wreckage from the collision between a Black Hawk helicopter and American Airlines Flight 5342 have been cleared from the Potomac River, officials said.

The wreckage of the Black Hawk helicopter that collided with an American Airlines plane over the Potomac River in Washington DC has been removed from the crash site and is being examined by the National Transportation Safety Board.