DC plane crash: A timeline of the deadly collision
Nearly 70 people are presumed dead in the incident.
Dozens of people are presumed dead after an American Airlines flight and military helicopter collided near Ronald Reagan Washington National Airport in Virginia on Wednesday night.
The Bombardier CRJ700 regional jet and Black Hawk helicopter both crashed into the icy Potomac River after colliding in midair, launching a desperate overnight search and rescue mission. No survivors are expected, officials said.
Sixty-four people were on the plane, which departed from Wichita, Kansas. Three Army soldiers were aboard the helicopter, which was on a training flight at the time, officials said.
Here's a look at how the tragedy unfolded, as the cause of the collision remains under investigation.

Wednesday, Jan. 29
5:38 p.m. CT: American Airlines Flight 5342 departs from Wichita, Kansas, headed to the D.C.-area airport, carrying 60 passengers and four crew members. The flight is scheduled to land in D.C. at 9:03 p.m. ET.
8:47 p.m. ET: A DCA air traffic controller asks the Black Hawk crew if they have the CRJ in sight and instructs the crew to pass behind the plane. A helicopter crew member confirms to the DCA tower a few seconds later that they have the plane in sight and will maintain visual separation, according to the ATC audio recording released by LiveATC.net.
8:47:58 p.m. ET: The time of the Black Hawk's last transmission.
8:48:01 p.m. ET: The time of the jet's last transmission.
Around that time, D.C. Fire and EMS receive an alert that an aircraft crashed while on approach to Reagan International Airport into the Potomac River, initiating a large local, state and federal response.
EarthCam footage from the Kennedy Center Cam captures an explosion in the air.

8:51 p.m. ET: Departures to DCA are grounded due to the aircraft emergency.
8:55 p.m. ET: DCA closes.
Around this time, Coast Guard Sector Maryland - National Capital Region command center watchstanders receive a report of the collision, with boat crews deployed to conduct searches.
8:58 p.m. ET: First responders arrive on the scene, with hundreds eventually responding from multiple agencies as they search into the night for any survivors.

Thursday, Jan. 30
At an early morning press briefing, D.C. Fire and EMS Chief John Donnelly says no survivors are expected from the plane crash and that crews are switching to a recovery operation.
Twenty-eight bodies have been recovered so far, including 27 from the plane and one from the Black Hawk helicopter, Donnelly says.
11 a.m. ET: DCA reopens, with planes now arriving and departing.

By the afternoon, dive teams cease operations on the Potomac River, having recovered all of the bodies of the victims they can without moving the fuselage, two sources familiar with the operation told ABC News. About 40 bodies have been recovered so far, including at least one of the soldiers from the Army helicopter, the sources said.
NTSB investigators announce in the evening that they have recovered the cockpit voice recorder and flight data recorder -- commonly known as the black boxes -- from the submerged jet and have taken them to the agency's labs for evaluation.
Runway 33, the runway where Flight 5342 had been cleared to land, will remain closed until Feb. 7.