All 67 people on board an American Airlines flight and a Black Hawk helicopter that collided in midair while the plane was landing at Ronald Reagan Washington National Airport near Washington, DC, are believed to be dead, according to officials.

This is the deadliest aviation tragedy in the United States since November 12, 2001, when an American Airlines plane crashed into a residential area of Belle Harbor, New York, shortly after taking off from John F Kennedy International Airport in New York City, killing 260 passengers on board and five people on the ground.

Here is what we know about the victims of Wednesday’s crash, what happened and what the initial investigations suggest might have contributed to the accident.

How did the plane crash unfold?

Flight 5342, operated by American Eagle, a regional branch of American Airlines, was flying from Wichita, Kansas, to the airport just outside Washington, DC. As it approached Ronald Reagan airport about 9pm on Wednesday (02:00 GMT on Thursday), the aircraft collided with a Sikorsky Black Hawk army helicopter.

Shortly before landing, the plane’s pilots were asked to change runways. While the plane was initially supposed to land on the main runway 1, the plane was asked to pivot to runway 33, which is much shorter. Flight tracking maps showed that the pilots accepted this request and adjusted the plane.

Fewer than 30 seconds before the crash took place, an air traffic controller asked the army helicopter if it could see the plane.

“PAT25 [army helicopter], do you have a CRJ [American Airlines plane] in sight? PAT25, pass behind the CRJ,” an air traffic controller said at 8:47pm.

A short time later, air traffic controllers could be heard saying, “Crash, crash, crash, this is an alert three.”

The two aircraft crashed into the Potomac River. The cause of the collision is not known yet.

Were there any survivors?

The American Airlines flight was carrying 60 passengers and four crew members while the Black Hawk had three US army soldiers on board.

“We are now at a point where we’re switching from a rescue operation to a recovery operation. At this point, we don’t believe there are any survivors from this accident,” Washington, DC, Fire Chief John Donnelly said in a televised statement on Thursday.

How many bodies have been recovered?

Donnelly added that the bodies of 27 people have been recovered from the plane while one body has been recovered from the helicopter. Separately, a law enforcement source told CBS News that at least 40 bodies have been recovered.

What do we know about the investigation so far?

The National Transportation Safety Board (NTSB) is carrying out an “all-hands-on-deck” investigation into the crash, Chairwoman Jennifer Homendy said during a news conference on Thursday.

The NTSB is an independent federal agency that investigates civil aviation accidents in the US as well as serious incidents related to other modes of transportation.

On Friday, the NTSB announced it had found the black boxes from the plane. Black boxes record flight data, pilots’ conversations and radio communications during flights. These recorders provide significant information in investigating aviation incidents because they can reveal pilot actions or external factors that might have contributed to accidents.

“The recorders are at the NTSB labs for evaluation,” the agency said in a post on X.

While the investigation is at an early stage, multiple US media outlets, including The New York Times and NBC News, have quoted unnamed sources as saying there was an air traffic controller shortage on Wednesday night at Reagan airport.

While normally there is one air traffic controller for planes and another one for helicopters, the same person was handling both planes and helicopters on Wednesday night.

For the investigation, the NTSB will form working groups to look into different areas connected to the accident, according to NTSB board member Todd Inman.

Inman explained that these groups would include: operations, investigation crew member duties and flight histories; power systems, looking into aircraft engines; structures, documenting the accident scene and air frame wreckage; survival factors, looking into injuries sustained; systems, looking into electrical, hydraulic and pneumatic components of the plane and helicopter; and an air traffic control group.

The NTSB has not said how long the investigation would take, but investigations into aviation incidents can take one to two years. The agency typically releases a preliminary report a few weeks after the accident that contains information collected at the scene.

Who were the victims of the plane crash?

Little is known yet about the three soldiers on the helicopter.

On the American Airlines flight, 14 people were affiliated with the figure skating community and were returning home from a national figure skating development camp for young skaters in Wichita, Skating Club of Boston CEO Doug Zeghibe said on Thursday.

They included a Russian world champion skating couple as well as two teenage figure skaters and their mothers.

Here is more about the victims:

Samuel Lilley

Lilley, 28, was one of the American Airlines pilots killed in the incident, Lilley’s father, Timothy Lilley, confirmed in a Facebook post and comments to the media.

Timothy Lilley wrote that his son was “doing great” in his career and personal life and was to have been married this year.

“Now it hurts so bad I can’t even cry myself to sleep. I know I’ll see him again but my heart is breaking,” he wrote in the post.

Jonathan Campos

Flight captain Campos, 34, was also killed, according to a fellow pilot, CNN reported.

His alma mater, Florida-based Embry‑Riddle Aeronautical University, released a statement saying the institute was “deeply saddened to learn of the passing of Captain Jonathan Campos”.

The statement added that Campos graduated with an aeronautical science degree in 2015.

Vadim Naumov and Evgenia Shishkova

A married Russian couple – Naumov, 55, and Shishkova, 52 – were figure skating coaches. Naumov and Shishkova won the world championship in pairs figure skating in 1994.

The couple moved to the US in the 1990s and became skating coaches.

Kremlin spokesman Dmitry Peskov confirmed on Thursday that the couple was on the flight. “We are sorry and send condolences to the families and friends who lost those of our fellow citizens who died in the plane crash,” he said.

They are survived by their son, Maxim Naumov, 23, who earned fourth place at the US national championships in Wichita on Sunday. Maxim Naumov, who was born in the US, was not on the flight.

Jinna and Jin Han

The Skating Club of Boston also said figure skater Jinna Han and her mother, Jin Han, were also killed in the crash.

“We watched Jinna just grow up here from just a tiny little tyke into this amazingly mature 13 year old,” Zeghibe said.

Spencer and Christine Lane

The Skating Club said Spencer Lane, 16, and his mother, Christine Lane, 49, were also killed.

The figure skater from Barrington, Rhode Island, would often post about his skating journey on his social media accounts, including TikTok.

On Wednesday, hours before the crash, he posted a photo on his Instagram story from inside the plane right before it took off from Wichita.

Spencer Lane was adopted from South Korea in 2008 by Christine and Doug Lane, his father told US media outlet NewsNation.

Doug Lane said his son was a “force of nature” who started figure skating three years ago. “It’s just devastating,” he said.

Alexandr Kirsanov, Sean Kay and Angela Yang

A skating coach from Delaware, Kirsanov, 46, was also killed, his wife, Natalya Gudin, told ABC News.

Gudin said Kirsanov was accompanying two young ice skaters on the trip. She said she last spoke with her husband as he boarded his flight.

Kirsanov was the coach of young skating duo, Kay and Yang, who were also on the flight. Their ages are unclear at the moment.

Olivia Ter

Ter, 12, was a figure skater from Maryland and was also on the plane, according to a statement by the Maryland-National Capital Park and Planning Commission.

Ian Epstein

Epstein, 53, was an American Airlines flight attendant who was also killed in the crash, Epstein’s sister Robbie Bloom confirmed to CNN.

The flight attendant is survived by two children and two stepchildren.

Asra Hussain Raza

Hussain Raza, 26, was also killed in the accident, her father-in-law told CNN.

Hussain Raza was a daughter of Indian immigrants and was a consultant based in Washington, DC. She would travel to Wichita twice a month to work on a project for a hospital there.

Other victims identified

Other victims who have been identified by local media so far include Wendy Jo Shaffer, Brielle Beyer, Justyna Beyer, Grace Maxwell and Casey Crafton.