The military helicopter that collided with an American Airlines flight over Washington, DC, was flying nearly twice as high as it should have been.

Figure skaters and coaches returning from the U.S. national championships were aboard the American Airlines flight that collided with a Black Hawk helicopter Wednesday.

An extensive search and rescue operation is currently under way after an American Airlines flight collided in mid-air with a helicopter in Washington DC, with both crashing into the Potomac River. Emergency services chief John Donnelly has said conditions are "extremely rough" in the dark and with icy temperatures.