An American Airlines flight carrying dozens of passengers has collided with a military helicopter as it approached Washington DC's Ronald Reagan National Airport.
The plane then crashed into the Potomac River, officials said, and boats and divers are searching the water for survivors.
The Bombardier CRJ700 regional jet - carrying 60 passengers and four crew members - collided with the helicopter as it was approaching the runway at around 21:00 EST (02:00 GMT) on Wednesday.
The plane was coming from Wichita, Kansas, according to the airline.
The crashed plane has split in half in the Potomac River with boats and divers now searching for people, US media reports say.
Three US army soldiers were onboard the Black Hawk military helicopter that collided with the jet, a defence official said.
The helicopter had taken off from Fort Belvoir in Virginia.
US President Donald Trump said he had been "fully briefed on the terrible accident".
"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," he said in a statement.
Takeoffs and landings have been halted at the airport as emergency personnel respond to the incident, the airport wrote in a post on X.
The Federal Aviation Administration said it was conducting an investigation.
