ARLINGTON, Va. (AP) — Police boats combed the banks of the Potomac River on Friday, slowly scanning the shoreline under rainy skies as investigators sought clues into the midair collision that killed 67 people and raised questions about air traffic safety around the nation's capital.
Watch the briefing in the player above.
No one survived the Wednesday night collision between the commercial airliner and an Army helicopter. The remains of 41 people had been pulled from the river as of Friday afternoon, including 28 that had been positively identified, Washington, D.C., Fire Chief John Donnelly Sr. said at a news conference. He said next of kin notifications had been made to 18 families, and that he expects the remains of all 67 people who died to eventually be recovered.
WATCH: What investigators revealed about the jet and helicopter collision in D.C. that killed 67
The wreckage of the plane's fuselage will probably have to be pulled from the water to get all the bodies, he said.
"This is heartbreaking work," Donnelly said, noting that more than 300 responders were taking part in the effort at any one time, including teams of divers and two U.S. Coast Guard cutters, at least one of which carries a crane. "It's been a tough response for a lot of our people."
It was unclear how long the recovery operation would take.
"We're working as fast as we can," he said. "We need your patience."
Although Ronald Reagan National Airport has reopened, two of its three runways remain closed to keep aircraft from flying over the crash scene while taking off or landing, said Terry Liercke, the airport's vice president and manager. Roughly 100 flights were canceled Friday.
Officials also heavily restricted helicopter traffic around the airport, an official said, hours after President Donald Trump claimed in a social media post that the Army Black Hawk had been flying higher than its allowed limit.
Investigators have recovered the cockpit voice recorder and flight data recorder of the American Airlines jetliner, which struck the chopper as the plane was coming in for a landing at the Washington-area airport. Officials are scrutinizing a range of factors in what National Transportation Safety Board Chairwoman Jennifer Homendy has called an "all-hands-on-deck event."
Investigators are examining the actions of the military pilot as well as air traffic control, after the helicopter apparently flew into the jet's path. Air crash investigations normally take 12-18 months, and investigators told reporters Thursday that they wouldn't speculate on the cause.
Authorities were still looking for the helicopter's black box recorder, Defense Secretary Pete Hegseth said Friday on Fox News Channel. Other factors in the crash, including the helicopter's altitude and whether the crew was using its night vision goggles, are still under investigation, he said.
Although some airspace had already been restricted following the crash, the Federal Aviation Administration decided to indefinitely bar most helicopters from using the low-to-the-ground routes that run under or parallel to the airport's flightpaths, an official told The Associated Press on Friday. The official spoke on the condition of anonymity because they were not authorized to discuss the matter.
Military aircraft frequently conduct such flights in and around the nation's capital for familiarization with routes they would fly in case of a major catastrophe or an attack on the U.S. that would require relocating key government officials.
The plane carried 60 passengers and four crew members. The remains of one of the three soldiers who were aboard the helicopter have been recovered.
Officials said flight conditions were clear as the jet arrived from Wichita, Kansas, carrying, among others, nine students and parents from Fairfax County, Virginia schools, a group of elite young figure skaters, their parents and coaches and a group of hunters.
READ MORE: Passengers on downed flight included young American figure skaters and Russian coaches
Details have been emerging about others who died in the crash, including Danasia Elder, a flight attendant on the American Airlines flight, WSOC-TV in Charlotte, North Carolina, reported.
Her brother-in-law, Brandon Payne, said she was married with two children and had dreamed of getting the airline job.
"She would want y'all to do the same thing she did. Chase your dreams, no matter what. Don't let nothing scare you, push you away. Just believe in yourself, believe in God, and follow the path," Payne said.
Debris from the crash has drifted miles (kilometers) downriver.
Dean Naujoks, who routinely patrols the Potomac for the environmental group Waterkeeper Alliance, on Thursday found floating debris that had been pushed by the wind and current into a pair of shallow coves along the Maryland shore.
The wreckage included pages from a flight manual, part of the plane's cabin wall, a woman's sweater, dozens of sugar packets with the American Airlines logo and what appeared to be the cushion from a pilot's seat. Naujoks, who had law enforcement permission to take his motorboat to the Woodrow Wilson Memorial Bridge, about 2 miles (roughly 3 kilometers) downriver from the crash site, turned the items over to the FBI.
"Everything is covered in jet fuel," Naujoks said Friday. "The sugar packets made me think of the flight attendants. I'm thinking of the people these things belonged to and it's a punch to the gut. It's just a sad day on the river."
Gomez Licon reported from Miami. AP writer Lea Skene contributed to this report. Writers Lolita C. Baldor, Tara Copp, Meg Kinnard, Chris Megerian, Aamer Madhani and Michael Biesecker contributed from Washington. Sarah Brumfield reported from Cockeysville, Maryland.