Investigators searching for wreckage from last week’s deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, conducted an overnight scan of the Potomac River where the aircraft fell using advanced imaging technology to map the riverbed and locate debris.

Salvage crews have been working to recover the wreckage of the American Airlines jet and the Black Hawk helicopter.

More than a week after the horrific helicopter-plane collision near Washington, salvage crews have recovered most of the wreckage.

Swedish police said on Tuesday five people were shot in an attack at a school in the city of Orebro some 200 km (125 miles) west of Stockholm, triggering a massive response by rescue services.

An American Airlines regional passenger jet and a U.S. Army Black Hawk helicopter collided midair and crashed into the Potomac River near Reagan Washington National Airport on Wednesday night. Officials have not provided a death toll but said all passengers and crew on both flights were feared dead.

The National Transportation Safety Board has released an update on the status of its investigation into the midair collision that occurred on Jan. 29 near Ronald Reagan National Airport, revealing that all major pieces from both the airplane and the helicopter involved have now been recovered from the Potomac River.