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.

The Army helicopter that collided with a passenger plane above the Potomac River boasted an experienced crew doing “an unforgiving job.” Friends and relatives are still baffled and mourning their loss.

The National Transportation Safety Board is examining new data that may indicate the Black Hawk helicopter involved in a fatal midair collision with American Airlines Flight 5342 near Washington, D.C.

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

The Unified Command said all 67 victims of the American Airlines and Black Hawk helicopter collision have been recovered and identified.