U.S. figure skaters, their coaches and family members were passengers on an American Airlines jet that collided with an Army helicopter near Ronald Reagan National Airport in Washington, D.C., and crashed into the Potomac River on Wednesday, U.S. Figure Skating said.

The figure skaters were returning from a development camp that followed the U.S. Figure Skating Championships in Wichita, Kansas.

“U.S. Figure Skating can confirm that several members of our skating community were sadly aboard American Airlines Flight 5342, which collided with a helicopter yesterday evening in Washington, D.C.,” U.S. Figure Skating said in a statement. “We are devastated by this unspeakable tragedy and hold the victims’ families closely in our hearts.”

U.S. Figure Skating did not identify any of the members of its team that were onboard the flight.

The flight carried 60 passengers and four crew members. The airplane collided with the helicopter while attempting to land, prompting a large search-and-rescue operation in the Potomac River.

There were multiple fatalities, a person familiar with the matter told The Associated Press, 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.

Russian media also reported that two Russian figure skaters were on board the flight, and a presidential spokesman expressed condolences to the families and friends of those killed in the plane crash.

“There were other of our fellow citizens there. Bad news from Washington today,” Russian presidential spokesman Dmitry Peskov said Thursday morning.

Russia’s figure skating federation expressed its condolences to those who had lost loved ones in the crash but said it was unable to comment further.

There was no immediate word on the cause of the collision, but all takeoffs and landings at 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,” Washington, D.C., 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.

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. ET when a regional jet that had departed from Wichita collided with a military helicopter on a training flight while on approach to an airport runway.

The crash 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 and the loss of altitude by the passenger jet.

Less than 30 seconds before the crash, an air traffic controller asked the helicopter if it had the arriving plane in sight. The controller made another radio call to the helicopter moments later: “PAT 25 pass behind the CRJ.” Seconds after that, the two aircraft collided.

Some 300 first responders were on scene. Inflatable rescue boats were launched into the Potomac River from a point along the George Washington Parkway, just north of the airport, and first responders set up light towers from the shore to illuminate the area near the collision site. At least a half-dozen boats were scanning the water using searchlights.

“It’s a highly complex operation,” D.C. fire chief John Donnelly said. “The conditions out there are extremely rough for the responders.”

The last fatal crash involving a U.S. commercial airline occurred in 2009 near Buffalo, New York. Everyone aboard the Bombardier DHC-8 propeller plane was killed, including 45 passengers, 2 pilots and 2 flight attendants. Another person on the ground also died, bringing the total death toll to 50.

Wednesday’s collision recalled the crash of an Air Florida flight that plummeted into the Potomac on Jan. 13, 1982, that killed 78 people. That crash was attributed to bad weather.

Reuters contributed to this report.