Authorities say that 28 people have been identified following Wednesday's fatal air crash near Washington DC, and expect to find all the bodies of the victims - so far, the remains of 41 have been recovered
Helicopter traffic around Ronald Reagan Washington National Airport has been restricted, which Secretary Sean Duffy says will ensure the safety of plane and helicopter traffic
President Trump says the helicopter involved "was flying too high" - but does not provide any evidence to back up the claim
White House spokeswoman Karoline Leavitt told reporters that the president "based that statement on the truth" from briefings he has received
An investigation is under way to establish what caused the collision between the US army helicopter and an American Airlines passenger plane, killing 67 people
Investigators have already recovered the flight data recorders, known as black boxes, from the wreckage of the passenger plane - a preliminary report into the crash will be issued in 30 days
Ros Atkins on... the Washington DC plane crash
Public officials, including Washington Mayor Muriel Bowser, are expected to give a briefing at around 12:30 am EST (05:30GMT) on the crash.
Newly confirmed Homeland Security Secretary Kristi Noem has said that she is deploying the US Coast Guard to help with search and rescue.
Rachel Looker
Reporting from East Potomac Park
I've been chatting with more people who have gathered at Hains Point to view the crash.
Camille DuBois biked here from her apartment about 15 minutes away. She says one of her friends is obsessed with planes and saw the crash on FlightTracker. He told her about it and she decided to come to the park.
"I read a lot about plane crashes because I have a lot of anxiety," she says.
DuBois has spent about 30 minutes at the park. She says she hasn't seen any damage and the scene has looked the same since she arrived.
"It's pretty crazy," she says.
Hamaad Raza says he was waiting at Reagan Washington National Airport for his wife, who was on board the American Airlines aircraft, when news of the crash reached him.
“She texted me that she was landing in 20 minutes," he told the local affiliate of CBS News, the BBC's US partner.
"I am just praying someone is pulling her out of the river right now."
Thomas Mackintosh
Live reporter
Image source, ReutersAll flights in and out of Reagan Washington National Airport have been grounded until at least 05:00 in the morning
It has just gone midnight in Washington DC and 05:00 here in London - if you are just joining us let's bring you up to date with everything we know so far:
Police officials have told the BBC's US partner CBS News that 18 bodies have been recovered by search crews at the scene of the crash, and that no survivors have been found so far.
There has not yet been an official update from authorities on the number of casualties, but we are expecting a news briefing soon.
The media chief of Joint Task Force-National Capital Region, which is part of the US Army, tells CBS News, the BBC's US partner, that the Black Hawk military helicopter that was involved in the crash was on a training flight.
Heather Chairez adds that it belonged to B Company, 12th Aviation Battalion out of Fort Belvoir in Virginia.
Two local residents tell local media of how they found out about the incident on the Potomac River.
One man, Jimmy Mazeo, says he noticed the plane flight patterns dispersing from their regular ones in the sky, and then saw what looked like a "white flare" in the sky.
"We thought they were shooting stars" he says, adding that he didn't "think much of it" until he saw the emergency services arriving at the scene.
Watch in full below.
Watch: Witness describes seeing ‘white flare’ at moment of plane collision
The Association of Flight Attendants, which represents 55,000 flight attendants across 20 airlines, said two of their members were on board the flight that crashed into the Potomac.
"While we mobilize to support the families and crews directly affected by this incident, we are also sending strength to all first responders doing everything they can to bring survivors to safety," the association's president said in a statement.
"We ask the public to keep the families in your thoughts and respect efforts to get information to loved ones first as everyone clings to hope for survivors."
“Let us all stay focused on saving lives," the organisation added.
The FBI has released a statement from its Washington field office saying they are helping in the response to the mid-air collision.
Here's the agency's statement in full:
"The FBI Washington Field Office’s National Capital Response Squad is responding to an aviation incident at Ronald Reagan Washington National Airport in support of our law enforcement and public safety partners. Please direct questions regarding this incident to the National Transportation Safety Board."
We have just gotten a statement from the Army, provided by the Pentagon. It says:
"We can confirm that the aircraft involved in tonight’s incident was an Army UH-60 helicopter out of Fort Belvoir, Virginia. We are working with local officials and will provide additional information once it becomes available.”
Fort Belvoir is a massive installation about 15 miles from the airport, near Mount Vernon, George Washington's home.
Flights that were supposed to land at Reagan National Airport are being diverted to Dulles International Airport, about 28 miles away, and the Washington DC metro system will stay open late to run extra trains to transport disembarking passengers into Washington, the transport authority's general manager says.
The transit system is also sending "warming buses" to the rescue scene for those working in the cold, according to General Manager Randy Clarke.
We're now hearing from those who witnessed the mid-air collision.
Ari Schulman said he saw a "stream of sparks" that resembled "a giant roman candle".
He told NBC Washington that he was driving on George Washington Parkway, which runs along the airport, and spotted the plane landing. He noted he often sees planes landing at the airport along the drive and watched as it approached.
Everything looked normal, he told the outlet. "It was level, nothing was wrong."
Schulman turned, and by the time he looked back, it "looked very, very wrong".
The plane looked like it had banked hard to the right, maybe 90 degrees, he said. "I could see the underside of the plane, and it's very, very dark out, so you shouldn't be able to see the underside of the plane."
Schulman said it was illuminated bright yellow and there "was a stream of sparks underneath it. It looked to me like a giant roman candle". He said the sparks went from the nose of the plane to the tail.
He looked back at the road but didn't hear any explosion or any boom. He looked for proof of a crash but there wasn't any fire.
"I looked back to see a fireball. I looked back to see a crash, something, and I didn't see anything. It looked completely normal," he told NBC. "My first thought was to wonder if I was hallucinating. If there had just been this horrible plane incident, why didn't I see anything afterward?"
He said as he drove through the area he started seeing the swarm of first responders.
Police and fire department divers are continuing to search water for survivors, with police boats assisting, a DC police official has told our US partner CBS News.
Reagan National airport is just across the river from Washington DC in Virginia.
Maryland's Governor, Wes Moore, says the state is closely monitoring the collision and has sent divers to the scene to help assist with the rescues.
"The State of Maryland and local authorities are engaged in response," Moore wrote in a post on X, adding that there were no disruptions at the Baltimore airport for now.
Moore's state of Maryland is just on the other side of the District of Columbia from Virginia.
Cai Pigliucci
Reporting from Reagan National Airport
We’ve just arrived on the scene at the airport.
From Reagan National, you can see many flashing lights down on the tarmac and what looks to be the search and rescue operation in the Potomac River - where the airplane and helicopter crashed - just beyond that.
It is an eerie silence in the skies as no flights can now fly in or out here - other than one helicopter above that seems to be patrolling.
There are workers directing traffic near us as people come to pick up those left at the airport.
Our reporters are on the scene at Reagan National Airport, where the flight that crashed nearby was meant to land.
Rescue efforts are visible in the photos behind the airport, also known as DCA.
Multiple agencies, including local police and federal officials, are involved in the rescue mission.
We reported earlier the Black Hawk Army helicopter involved in the crash had been carrying three US soldiers.
Now the BBC'S US partner CBS News has spoken to a US defence official who says the helicopter had taken off from Fort Belvoir, Virginia, which is south-west of Ronald Reagan National Airport.
We have gotten an updated statement from American Airlines.
It says, in part:
"American Eagle Flight 5342 en route from Wichita, Kansas (ICT) to Washington, DC (DCA) was involved in an accident at DCA. The flight was operated by PSA Airlines with a CRJ-700.
There were 60 passengers and four crew members on board the aircraft.
Our concern is for the passengers and crew on board the aircraft. We are in contact with authorities and assisting with emergency response efforts."
While we still don't know how many casualties there have been, we're just receiving some information on the search and recovery mission.
According to reports by US media, the American Airlines plane that crashed is split in half in the Potomac River, with boats and divers searching for people.
The helicopter that was involved in the crash is near the plane, upside down in the water, US media report.
US President Donald Trump says he has been "fully briefed on the terrible accident which just took place at Reagan National Airport".
"May God Bless their souls," he says in a statement.
"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.”