Aviation experts have warned for years about near collisions at airports around the US, citing air traffic control shortages and airspace congestion.

The collision involved a Bombardier CRJ700 regional jet operated by PSA Airlines and a military Black Hawk helicopter.

It's been more than two decades since American Airlines, the nation's largest carrier, was involved in a deadly crash.

The mid-air crash was reported near Reagan Washington National Airport late Jan. 29. At least 28 people have been found dead as crews continue to search the Potomac River, according to the Federal Aviation Administration and the Associated Press. No survivors are expected to be found.

A regional jet collided with an Army Black Hawk helicopter near Ronald Reagan Washington National Airport on Wednesday evening, U.S. officials confirmed to ABC News.

Before Wednesday’s crash near Washington, D.C., there had not been a fatal collision involving a commercial aircraft in the United States since 2009.

In 2018, a passenger on a Southwest Airlines jet was killed after shrapnel from the plane's engine crashed through a window and caused such a drop in air pressure that a passenger suffered fatal injuries after nearly being sucked outside. It was the first death on a U.S. airline flight since 2009.

Air traffic controllers asked Flight 5342 to switch runways when coming in to land. Black box recordings from the jet and the military helicopter it collided with will help reveal if this contributed to the accident.

Search efforts continue after an American Airlines plane from Wichita, with 64 people on board, collided with an Army helicopter near Washington, D.C., and crashed into the Potomac River.

Wednesday's crash involving an American Airlines flight and Black Hawk helicopter marked the first commercial crash on U.S. soil in more than 15 years.

A regional jet carrying 64 people collided with an Army Black Hawk helicopter. Reagan National Airport grounded all flights.

Secretary of Transportation Sean Duffy said Americans should be assured that "you're safe" when flying in the wake of a deadly crash between a commercial airliner and an Army helicopter.