MBANGA-PONGO, Cameroon_Crash investigators concentrated Monday on the possibility that a Kenya Airways jetliner lost power in both engines during a storm and tried to glide back before plunging nose first into a mangrove swamp 20 kilometers (12 miles) from the airport.
All 114 people on board were killed in the crash early Saturday, officials said.
The Nairobi-bound Boeing 737-800 sent a distress signal a shortly after takeoff Saturday from Douala, delayed an hour by storms, and then lost contact 11 to 13 minutes later. It took more than 40 hours to locate the wreckage, most of it submerged in murky orange-brown water and concealed by a thick canopy of trees.
"The plane fell head first. Its nose was buried in the mangrove swamp," said Thomas Sobakam, chief of meteorology for the Douala airport. He said the plane disintegrated on impact.
There were no survivors, said Luc Ndjodo, a local government official. "We assume that a large part of the plane is underwater," he said. "I saw only pieces."
Late Monday, one of the plane's two black boxes was found - a development that could help determine what happened to Flight 507.
"We found it in the mud," said Bernard Atebede, prefect of the nearby town of Vouri. "I'm not an expert and so I don't know what kind of data is on it, but the technicians on the scene said that it should have the information we need to figure out what happened,"
However, it was not clear whether it was the data recorder or the cockpit voice recorder, or what condition the device was in, Capt. Francis Ekosso of the coast guard said.
The initial investigation is focusing on a theory that the plane lost power in both engines but did not have enough altitude to glide back to the airport, a source close to the airline's investigation in Kenya, who spoke on condition of anonymity because he is not authorized to speak to the press.
The wreckage was found along the plane's expected flight path, and procedures for losing all power call for the pilot to try to return to the airport along the same path.
A nosedive crash also is consistent with a plane stalling as a pilot desperately tries to coax the plane farther along the glide path.
At the crash site, debris lay scattered over a small area roughly the size of soccer field. Much of it, including some hanging from trees, was shredded beyond recognition. But smaller items were intact: a white tennis shoe, a black purse of braided leather, a length of orange-and-blue cloth perhaps worn as a skirt.
"It's a scene of horror," Atebede said. "I saw things that should never be seen. It makes you realize the fragility of life."
He said 20 bodies have been recovered, and DNA testing would be used to determine the identities of some.
Workers carried the bodies and body parts on stretchers for the 20-minute hike through the swamp to ambulances. Trees had been chopped down and placed over puddles to make the walk easier.
Among the 105 passengers on board was Nairobi-based Associated Press correspondent Anthony Mitchell, 39, who had been on assignment in the region. Nine crew members also were on board.
Initially, the search focused on the rugged, forested area near Lolodorf, about 140 kilometers (90 miles) southeast of Douala. Sobakam said officials were led astray by an incorrect satellite signal, possibly emitted from the plane.
But fishermen living in the swampy mangroves near the airport reported hearing a loud sound at the time of the crash.
Officials wanted to know if the storms caused the plane to lose power in both engines and if a power failure caused the aircraft's own radar to fail.
"Whatever happened must have happened very fast, which is usually a sign of catastrophic structural failure," said Patrick Smith, a U.S. based-airline pilot and aviation expert.