American Airlines plane, helicopter collide midair near D.C.-area ...

A commercial airplane collided in midair with a Black Hawk helicopter as the jet was approaching a runway at Ronald Reagan Washington National Airport on Wednesday night, according to federal aviation officials.

The accident happened as the jet, operated by regional carrier PSA Airlines on behalf of American Airlines, was attempting to land just before 9 p.m. ET.

There was no immediate word on fatalities. But the incident could be the most significant disaster in U.S. airspace in at least 15 years.

American Airlines said there were 60 passengers and four crew members on board the jet, a Bombardier CRJ-700. "Our concern is for the passengers and crew on board the aircraft. We are in contact with authorities and assisting with emergency response efforts," the airline said in a statement.

The Pentagon told NPR that the Army Black Hawk helicopter had three soldiers on board and was out of Fort Belvoir, Va.

A webcam at the nearby John F. Kennedy Center for the Performing Arts showed a small aircraft, presumably the helicopter, colliding with the passenger jet at a low altitude, followed by a bright explosion. Radar tracking sites show the passenger jet appears to have fallen into the frigid Potomac River.

The jet, operating as American Eagle Flight 5342, had departed from Wichita, Kan., and was attempting to land on Runway 33 at Reagan airport (DCA).

DC Fire and EMS confirmed that a small aircraft crashed into the Potomac River near the airport, as helicopters and fireboats rushed to the scene to search for survivors. "There are multiple partner agencies coordinating a search and rescue operation in the Potomac River," according to a news release from DC Fire and EMS and the Metropolitan Police Department.

The airspace in and around DCA is complicated due to challenging approaches into the airport as well as flight restrictions above government buildings. It's particularly busy airspace too with an influx of police and military helicopters operating in the area.

Officials in Wichita have activated an "incident family support team" at the Wichita Dwight D. Eisenhower National Airport. Some family members of those on board Flight 5342 were there meeting with a chaplain, NPR's Brian Mann reported.

In a statement from the White House, President Trump said, "I have been fully briefed on the terrible accident which just took place at Reagan National Airport. May God Bless their souls. Thank you for the incredible work being done by our first responders. I am monitoring the situation and will provide more details as they arise."

The last major commercial airplane accident in the U.S. occurred in 2009, when a Colgan Air flight crashed near Buffalo killing a total of 50 people (49 passengers and crew, and one person inside a house).

The FAA and the National Transportation Safety Board will investigate.

This is a breaking news story and will be updated.