ROMULUS, MICH., AUG. 21 -- --

Uncertainty for some families of the victims of the nation's second-worst air disaster ended today with release of a coroner's list of 155 identified victims, but theories on the cause of the crash remained in dispute.

The Wayne County medical examiner's office said the list includes 147 passengers aboard Northwest Airlines Flight 255, six crew members and two victims on the ground. Authorities have said they think that at least 158 people were killed in the Sunday night crash at Detroit Metropolitan Airport.

A 4-year-old girl, Cecilia Cichan, was the lone survivor. She remained hospitalized in Ann Arbor in serious but improving condition.

Meanwhile, the National Transportation Safety Board, which may not release its final report on the cause of the crash for nine to 12 months, prepared to conclude its on-site investigation. The investigation team plans to stay in Detroit for three to four more days, a spokesman said.

Much of the investigation concerns whether the plane's flaps and slats, panels along the leading and trailing edges of the wing that help provide lift during take off, had been extended.

Investigators said they had yet to determine how the panels were positioned at the time of the crash.

Two witnesses have said the plane's flaps were extended as it was taking off, contradicting indications in one of the plane's "black boxes" that the flaps were retracted. The extended flaps and slats provide crucial lift for takeoff.

One of the top investigators, NTSB board member John K. Lauber, said yesterday after returning to Washington that the copilot of a Northwest plane awaiting takeoff "was very positive" that the doomed jet's flaps were in the proper position.

And Raymond Peller, a Romulus truck driver and licensed private pilot who was watching air traffic near Flight 255's runway, said, "The flaps were down when they were in front of me and went up in the air."

Today, however, NTSB spokeswoman Rachel Halterman said physical evidence presented "conflicting and confusing" information about the position of the flaps and slats.

The physical evidence made it seem that the flaps were retracted but investigators "were not comfortable that that is a fact," Halterman said.

"On the slats, there is evidence to indicate they were extended and evidence to indicate they were retracted," she said.

Metalurgical tests performed on the wreckage at NTSB laboratories would help investigators determine the configuration of the panels at the time of the crash, she said.

ABC News quoted unnamed sources today as saying that investigators were checking to see whether the crew intentionally disabled a warning system that would have indicated that the flaps were not in the proper position.

The system had gone off in the past when there was no problem, ABC said.

NTSB officials stressed that no final determination has been made about the cause of the crash, and that weather conditions, aircraft weight, cargo distribution and other factors could have contributed.