LISSA, Nigeria — Investigators searched the still-smoldering wreckage of a jetliner that slammed into the Nigerian bush, seeking flight-data recorders and other clues Monday to the cause of the crash that killed all 117 people aboard.

After much confusion about whether anyone had survived in the immediate aftermath of the Saturday evening crash, Nigerian officials confirmed Monday that all passengers and crew were dead.

State Department spokesman Edgar Vasquez said one American aboard the flight had been killed, but he did not identify the person.

Fidelis Onyenyiri, chief of the National Civil Aviation Authority, said the crash appeared to be an accident.

"The weather was not too bad, but there was lightning, and an airplane struck by lightning could lose total control," Onyenyiri told reporters on Sunday. "So there is a likelihood of a natural cause."

The impact appeared to cause the plane's virtual disintegration. Small bits of fuselage, human flesh and clothing were strewn in nearby trees. A hand and leg lay on the ground.

Acrid smoke still curled from the eight-yard-deep pit as investigators picked through wreckage, looking for flight-data recorders — the so-called black boxes, which are actually often blaze orange for easier identification.

The plane lost contact with the Lagos control tower five minutes after taking off from Murtala Muhammed International Airport in Lagos at 8:45 p.m. on Saturday, said Jide Ibinola, a spokesman for the Federal Airport Authority of Nigeria. State radio said pilots issued a distress call before the plane disappeared from radar.

The Bellview Airlines Boeing 737-200 was headed to the capital, Abuja, on what was supposed to have been a 50-minute flight, a route popular among Nigerians and expatriates.