Officials say the conditions of the Potomac River are complicating recovery efforts of the bodies of the 67 presumed dead in a mid-air collision between American Airlines flight 5342 from Wichita and a military Black Hawk helicopter.

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

Divers are expected to return to the Potomac River as part of the recovery and investigation after the United States’ deadliest aviation disaster in almost a quarter century