DC plane crash live updates: Investigators comb through wreckage for clues

Investigators with the National Transportation Safety Board are now examining the wreckage from the midair collision of the regional American Airlines jet and Army Black Hawk helicopter near Reagan National Airport.

The NTSB shared a video of investigators as they combed through the debris.

The agency said all major pieces of both the jet and the helicopter have been taken to a secure airport facility for further examination. Investigators are looking for marks on the aircraft that could provide clues to the angle of collision.

All major parts of the American Airlines regional jet and Black Hawk helicopter have been removed from the Potomac River after last week's crash, the U.S. Army Corps of Engineers announced Thursday.

Salvage crews will continue to work on clearing smaller debris from the river.

The crews began removing the wreckage from the Jan. 29 crash on Monday.

The pilots of the U.S. Army Black Hawk helicopter that collided with the regional American Airlines jet last week, were believed to be wearing night vision goggles at the time of the crash, an official said.

“We do believe, given the mission and given what we’ve heard or not heard on the [cockpit voice recorder] that they were wearing night vision goggles,” National Transportation Safety Board Chair Jennifer Homendy said during a press gaggle Thursday.

She said that's according to NTSB's preliminary information.

Homendy also said the NTSB did not know for sure that the Automatic Dependent Surveillance-Broadcast (ADS-B) tracking system was installed on the helicopter and the agency is awaiting further evaluation.

Earlier, Sen. Ted Cruz, of Texas, said lawmakers were briefed by the Federal Aviation Administration and told that the data from the ADS-B system in the helicopter was "turned off."

-ABC News' Ayesha Ali and Clara McMichael

Pieces of the downed Black Hawk helicopter were removed from the Potomac River on Thursday as the investigation into the cause of the crash continues.