There were multiple fatalities, according to a person familiar with the matter, but the precise number of victims was unclear as rescue crews hunted for any survivors

Three soldiers were onboard the helicopter, an Army official said

There was no immediate word on the cause of the collision, but all takeoffs and landings from the airport were halted as dive teams scoured the site and helicopters from law enforcement agencies across the region flew over the scene in methodical search for bodies

"We are going to recover our fellow citizens," District of Columbia Mayor Muriel Bowser said at a somber news conference at the airport Thursday morning in which she declined to say how many bodies had been recovered

Sen. Roger Marshall of Kansas said, "When one person dies it's a tragedy, but when many, many, many people die it's an unbearable sorrow"

President Donald Trump said he had been "fully briefed on this terrible accident" and, referring to the passengers, added, "May God Bless their souls"

The Federal Aviation Administration said the midair crash occurred before 9 p.m. EST when a regional jet that had departed from Wichita, Kansas, collided with a military helicopter on a training flight while on approach to an airport runway. It occurred in some of the most tightly controlled and monitored airspace in the world, just over three miles south of the White House and the Capitol

Investigators will try to piece together the aircrafts' final moments before their collision, including contact with air traffic controllers as well as a loss of altitude by the passenger jet

American Airlines Flight 5342 was inbound to Reagan National at an altitude of about 400 feet and a speed of about 140 miles per hour when it suffered a rapid loss of altitude over the Potomac River, according to data from its radio transponder. The Canadian-made Bombardier CRJ-701 twin-engine jet, manufactured in 2004, can be configured to carry up to 70 passengers