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.

Army Blackhawk helicopter that collided with an American Eagle flight over the Potomac River​ late last month was flying with a safety system turned off, Sen. Ted Cruz told reporters after a briefing from the FAA and NTSB.