Federal investigators on Friday were mum on the cause of the accident that brought down a US Airways jetliner, declining to comment on whether reports of birds disabling the engines were true.
Kitty Higgins of the National Transportation Safety Board wouldn't theorize on what crippled the Airbus 320 passenger plane and prompted the pilot to do an emergency landing in the Hudson River, which separates New York and New Jersey.
"I don't want to speculate on what might have happened," Higgins said at a Friday afternoon news conference.
Both engines are missing from the aircraft, and crews were using sonar to search the river for them, according to Higgins.
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"Both engines are no longer attached to the plane," she said.
The Associated Press, meanwhile, reported that the pilot, Chesley B. "Sully" Sullenberger III, refused air controllers' calls for an emergency landing at one of two airports.
An unidentied source told the Associated Press that Sullenberger responded that he was "unable" to land at the airports, then said he'd go into the river instead.
It wasn't immediately clear whether he thought he couldn't reach the airports or didn't think he'd be able to stop the plane on the runway.
Higgins said the engines apparently came off after hitting the water, though it wasn't clear exactly when they detached from the rest of the aircraft. In a photograph of the plane as it approached the river, it appeared to have both of its engines.
Experts say it's not uncommon for engines to break apart from planes after bird strikes, because of the severe vibration brought on in such incidents.
Crews plan to begin hoisting the plane from the water about 10 a.m. Saturday before putting it on a barge and removing the flight data recorder and the cockpit voice recorder, according to Higgins.
She said one challenge will be hauling the plane out of the water without causing it to break apart.
"Once we get the flight data recorder it will give us the radar so we can figure out where the engine separated from the plane," said NTSB spokesman Peter Knudson.
After the recorders are removed, damage to the plane will be documented and the aircraft will be taken to a secure location for further investigation, according to Higgins.
Investigators brought in a giant crane, divers and a barge Friday to help pull a US Airways jetliner from the Hudson River.
In addition to focusing on recovering the black box, the NTSB also planned to interview the pilots on Saturday about the accident.
The Airbus A320, built in 1999, was tethered to a pier on the tip of Lower Manhattan on Friday morning — about four miles from where it touched down. Only a gray wing tip could be seen jutting out of the water near a Lower Manhattan sea wall.
Crews of NYPD divers went underwater to inspect the belly of the plane to make sure it was stable enough to lift and secure a bed of ropes underneath it.
Police and emergency crews also pulled about 15 pieces of carry-on luggage, the door of the plane, sheared pieces of metal and flotation devices from the water.
Federal Aviation Administration spokeswoman Laura Brown said there was no immediate indication the incident was "anything other than an accident."
As investigators scoured the wreckage of the Airbus A320, many of the 155 people aboard recounted survivor stories and hailed the pilot as a hero who delivered them from certain death.
Sullenberger, the pilot, was in good spirits and showing no outward signs of stress from the ordeal, a pilots union official said.
His wife, in an interview outside their California home, called him "a pilot's pilot" and said talk of him being a national hero was "a little weird."
A person briefed on Sullenberger's radio communications said the pilot considered emergency landings at two airports after his plane suffered a double bird strike, but twice told air controllers he was unable to make them.
He told controllers he planned to go into the river instead. The person spoke on condition of anonymity because of the ongoing investigation.
Air traffic controllers first gave Sullenberger directions to return to New York City's LaGuardia Airport, but he replied, "unable." Then he saw the Teterboro airstrip in the northern New Jersey suburbs, got clearance to go there, but then again responded, "unable." He then said he was going into the river.
It was not immediately clear when the engine broke off, but such scenarios can happen in bird strikes.
If the engine takes in a very large bird — or several birds at once — they could break several fan blades, causing an imbalance in the engine's rotation and severe vibrations, said Kevin Poormon, who tests the ability of aircraft engines to withstand bird strikes.
If the engine doesn't shut down right away, those vibrations conceivably could be strong to cause the engine to come loose from its mounting, Poormon said.
In a photograph of the plane as it approached the river, it appeared to have both engines.
Passengers were effusive in their praise for how Sullenberger, co-pilot Jeff Skiles and crew handled the landing and evacuation.
Mark P. Hood, of Charlotte, N.C., said he felt a jolt ripple through the jet as though a baseball bat hit the engine close to the George Washington Bridge.
"I think everyone was holding their breath, making their peace, saying their prayers," Hood said Friday.
Passenger Billy Campbell said he approached Sullenberger while they were standing on a rescue raft in the frigid cold.
"I leaned over and grabbed his arm, and I said I just want to thank you on behalf of all of us," Campbell told NBC's "Today" show. "He just said, 'You're welcome.'"'
The plane, bound for Charlotte, N.C., took off from LaGuardia Airport at 3:26 p.m. Less than a minute later, the pilot reported a "double bird strike" and said he needed to return to LaGuardia, said Doug Church, a spokesman for the National Air Traffic Controllers Association.
If the accident was hard to imagine, so was the result: Besides one victim with two broken legs, there were no other reports of serious injuries to the 155 people aboard.
Passengers quickly realized something was terrifyingly wrong.
"I heard an explosion, and I saw flames coming from the left wing, and I thought, `This isn't good,"' said Dave Sanderson, 47, who was heading home to Charlotte from a business trip.
Then came an ominous warning from the captain: "Brace for impact because we're going down," said passenger Jeff Kolodjay, 31.
The 150 passengers and five crew members were forced to escape as the plane quickly became submerged up to its windows in 36-degree water. Dozens stood on the aircraft's wings on a 20-degree day, one of the coldest of the winter, as commuter ferries and Coast Guard vessels converged to rescue them.
At a City Hall ceremony Friday to honor those who came to the aid of the stranded passengers, Mayor Michael Bloomberg said Sullenberger's actions "inspired people around the city, and millions more around the world."
Bloomberg planned to present the pilot with the key to the city.
Lorrie Sullenberger and her two daughters emerged from her Danville, Calif., home Friday and called her husband "a pilot's pilot who "loves the art of the airplane."
Sullenberger, 57, of Danville, Calif., is a former Air Force fighter pilot who has flown for US Airways for 29 years. He also runs a safety consulting firm.
Lorrie Sullenberger said hearing her husband's story "was really a shock. ... My husband said over the years that it's highly unlikely for any pilot to ever have any incident in his career, let alone something like this."
She called talk of her husband being a national hero "a little weird."
The pilot's sister, Mary Margaret Wilson, said she had a gut feeling her brother was at the controls when she heard a passenger plane safely landed in the Hudson River.
"When I first saw it on TV, they were saying it was an amazing landing, like one in a million. And I thought to myself, 'That's something my brother could do,"' said Wilson, a Dallas resident.
James Ray, a spokesman for the U.S. Airline Pilots Association, said he spoke with Sullenberger on Friday and described him as being "in good shape physically, mentally and in good spirits."
Ray said the flight crew was resting and likely would meet with investigators later Friday or Saturday. He said the crew has been asked not talk to the press about the accident until after the NTSB investigation is complete.
From 1990 to 2007, there were nearly 80,000 reported incidents of birds striking nonmilitary aircraft, about one strike for every 10,000 flights, according to the Federal Aviation Administration and the Department of Agriculture.
Thursday's river landing took place almost exactly 27 years after an Air Florida plane bound for Tampa crashed into the Potomac River just after takeoff from Washington National Airport, killing 78 people. Five people on that flight survived.
The Associated Press contributed to this report.