Washington DC air crash: What we know

A US commercial airliner with 64 people aboard and a military helicopter collided over Washington on Wednesday before crashing into the Potomac River, triggering a massive rescue operation that has pulled multiple bodies from the near-freezing water.

Here's what we know so far:

What happened? 

Just before 9:00 pm (0200 GMT) a Bombardier jet operated by American Airlines subsidiary PSA was approaching Ronald Reagan Washington National Airport when it collided with a military Black Hawk helicopter.

In footage taken from the Kennedy Center, Washington's cultural hub, the powerful lights of a descending airplane and the dimmer lights of another aircraft heading toward it can be seen until the collision, which produced a fireball.

The plane was coming from Wichita, in the central state of Kansas.

The helicopter was conducting a training flight, according to a military spokesperson.

Both aircraft crashed into the Potomac River, local authorities confirmed.

 Casualties unclear

American Airlines reported 60 passengers and four crew members were aboard the flight.

Three military personnel were on board the helicopter, according to a US military official.

Several hours after the accident, authorities had still not provided a toll of casualties -- even a provisional one.

But US media reported multiple bodies were recovered from the Potomac River.

CBS News, quoting a police official, said "at least 18 bodies were recovered", while NBC said "more than a dozen" had been found, citing two sources familiar with the search efforts.

Several members of the US figure skating community were aboard the jet, according to US media.

"We are devastated by this unspeakable tragedy and hold the victims' families closely in our hearts," the Washington Post reported, quoting a statement from US Figure Skating.

Russian news agencies meanwhile said the country's champion skating couple, Yevgenia Shishkova and Vadim Naumov, who won the 1994 world pairs title, were on board the plane.

Complex rescue operation

A large-scale and "extremely complex" search and rescue operation is underway.

Over 300 rescuer workers are mobilized in "extremely difficult" conditions, according to Washington Fire Chief John Donnelly.

"It's pitch dark. The water is cold and murky. These are very difficult conditions for divers," he said.

"There's wind, ice, it's dangerous."

Numerous inflatable boats were visible from the banks of the Potomac, where dozens of flashing lights could be seen, according to AFP reporters.

Helicopters sweeping the waters with powerful searchlights were also in action.

The Coast Guard has been called for reinforcement.

"We expect our operations to last several days," authorities said.

Was it avoidable?

The collision "should have been avoided," President Donald Trump said on social media.

"The plane was on a perfect approach path to the airport. The helicopter was heading directly toward the plane for some time. The night was clear, the lights of the plane were visible, why didn't the helicopter climb or descend, or make a turn?" he wrote.

"Why didn't the control tower tell the helicopter what to do instead of asking if they saw the plane? This is a bad situation that looks like it should have been prevented. NOT GOOD!!!"