Investigators searching for wreckage from last week’s deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, conducted an overnight scan of the Potomac River where the aircraft fell using advanced imaging technology to map the riverbed and locate debris.

Investigators revealed that the U.S. Army Black Hawk helicopter that collided with American Airlines Flight 5342 was flying about 100 feet higher than it should have been, and also stated the helicopter crew was warned about the incoming jet two times.

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.

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.

Investigators with the National Transportation Safety Board (NTSB) are examining the wreckage after an American Airlines plane and Black Hawk helicopter collided midair near Reagan National Airport (DCA),