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 National Transportation Safety Board says the helicopter must be recovered from the Potomac River so it can get more precise data.

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.

Crews working at the site of the deadliest aviation disaster in a generation have recovered all 67 victims of the collision between two aircraft over the Potomac River in Washington, DC, officials said Tuesday.

Divers and salvage crews have recovered the remains of all 67 victims of last week’s midair collision near Reagan National Airport, officials said Tuesday.

Every victim involved in the American Airlines commercial plane collision with a military helicopter last week has been recovered. Officials announced Tuesday that the remains of 67 people — 64 from the plane and three from the helicopter — have been recovered.

An American Airlines regional jet collided with a U.S. Army Black Hawk helicopter on Jan. 29. Both aircraft plunged into the Potomac River near Reagan Airport.

Authorities recovered all of the 67 victims from the Potomac River less than a week after an American Airlines flight collided with an Army Black Hawk helicopter in the Washington, D.C., area.