Investigators trying to figure out what led to the deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, last week will brief lawmakers Thursday on what they’ve learned after combing through data from both aircraft and air traffic control.

Wreckage of the military helicopter involved in a mid-air collision with an American Airlines passenger jet that killed all 67 people on both aircraft was recovered from the Potomac River, federal officials said.

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.