As recovery crews endure cold water and miserable rain Friday to attempt to pull more wreckage of American Airlines Flight 5342 and an Army Black Hawk helicopter from the Potomac River, investigators are intensifying their search for the collision’s cause – with initial concerns already raised about the path of at least one of the aircraft.

U.S. President Donald Trump said on Friday the Army Black Hawk helicopter that collided with a regional passenger jet in Washington, D.C. was flying too high at the time of the accident, in what appeared to be a major disclosure about the investigation.

A Black Hawk military helicopter and an American Airlines plane collided near Ronald Reagan Washington National Airport in Washington, D.C on Wednesday.