An airplane collided with a helicopter while trying to land at the Ronald Reagan Washington National Airport on Wednesday night, officials said.

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.

First thing is the communication between the air traffic control and the helicopter and the plane … There’s no direct communication between the civilian and the military helicopter and airplane. Instead,