American Airlines CEO Robert Isom said the National Transportation Safety Board, which is investigating the deadly midair collision between an American passenger jet and a military helicopter, will be the lone authority on the cause and details of the crash.

An American Airlines regional jet went down in the Potomac River near Ronald Reagan Washington National Airport.

Officials from the NTSB reiterated local authorities’ belief that there were no survivors in the deadly Wednesday, Jan. 29 midair collision between an American Airlines jet and a U.S. Army Black Hawk helicopter over the Potomac River in Washington,