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.

Six days ahead of schedule, officials on Tuesday announced the section of the Potomac River affected by the deadly collision between an American Airlines jet and military helicopter had been fully restored.

After American Airlines’ American Eagle Flight 5342 had a mid-air collision with a helicopter and subsequently crashed into the Potomac River, the D.C. fire chief shared a statement.

Crews have finished recovering the wreckage of a plane and helicopter that collided mid-air, killing 67 people.

The wreckage of a Black Hawk helicopter that crashed into a plane above the Potomac River has been recovered from the water. Footage captured by the National Transportation Safety Board shows the recovery of a Sikorsky UH-60 military helicopter from the river near Ronald Reagan Washington National Airport on 7.