Investigators have recovered the flight recorders—also known as black boxes—from both the commercial jet and the military helicopter involved in the mid-air collision near Reagan National Airport in Washington,

Rescue crews will return to the Potomac River on Friday morning as they continue searching for victims of Wednesday night’s deadly midair collision.

The crash and rescue on the icy river connecting Washington, DC and Virginia had similarities to this one. Five of the 79 aboard the flight survived.