ROMULUS, MICH., AUG. 17 -- Federal aviation officials said today that a fire in the left engine of a Northwest Airlines jetliner may have contributed to the crash that authorities said killed at least 154 people here Sunday night.

At a briefing tonight, John K. Lauber, the National Transportation Safety Board member in charge of the investigation, said there were no survivors among the 152 aboard the aircraft and that at least two persons appeared to have been killed on the ground.

Northwest's passenger count differed from that of the NTSB. The airline said there were 153 persons on board, including six crew members and three nonworking employes. The NTSB said only two nonworking Northwest employes were on board.

Lauber cautioned that it was far too early to tell what happened to the plane. He said it could be weeks, or even months, before anyone could hope to be certain what caused the fiery demise of Flight 255, which crashed at the edge of Detroit Metropolitan Airport moments after it took off at 8:45 p.m. Sunday.

"At this point we can rule nothing in and nothing out for certain," said Lauber. He did say that early indications showed no evidence of an uncontained fire in the engine that spewed shrapnel into the aircraft's belly, as earlier reports had indicated. Spewing shrapnel would be an indication that the engine was breaking up.

He also stressed that the airport tower was fully staffed with qualified controllers at the time of the crash.

Although the intensive investigation into the accident has just begun, safety officials have focused their initial attention on the jetliner's Pratt & Whitney JT8D engines, in large part because dozens of witnesses reported that the left side of the craft burst into flames before it hit the ground.

But Lauber said tonight that there were conflicting reports, that other witness said the plane was not engulfed in flames before it hit the ground.

"What scares the hell out of me is that it appears just to have gone up in flames," said one member of the investigation team. "That plane is a delight to fly, and at this point it looks like something horrible happened to that engine."

More than 100 federal officials began searching for clues to the fatal crash today, sifting carefully through the twisted wreckage while scores of volunteers carried the dead to a makeshift morgue near the crash site.

Federal safety officials now say that at least 154 people died when, only 500 yards beyond the runway, one wing of the plane hit a light pole on a National Car Rental lot and the other hit an Avis car rental building. The jetliner then became a ball of fire and rammed a railroad trestle and two Interstate 94 overpasses.

Only one accident in U.S. aviation history, the May 25, 1979, crash of an American Airlines DC10, which killed 275 in Chicago, has taken more lives. In 1982, 154 persons died in the crash of a Pan American World Airways Boeing 727-200 in Kenner, La.

Northwest released the names of crew members and off-duty Northwest employes on the flight, but said it would not release a passenger list because not all those aboard have been identified. The Associated Press identified some passengers through relatives.

Among those confirmed killed in the crash, however, was Nick Vanos, the backup center for the Phoenix Suns basketball team. {Details on Page C1.}

NTSB officials said that of the 152 people on the plane, 144 were passengers, six were working crew members and two were Northwest Airlines pilots not working on the flight.

It was still not certain today whether more than two people were killed on the ground by the crash. There were numerous injuries. Wayne County law enforcement officials said that it may take days to identify all the bodies.

There were reports that a 4-year-old girl may have survived the flight. But tonight NTSB officials said that all those aboard the plane were dead and they assumed the child was a passenger in a car that was struck by part of the plane.

She was reported in critical condition at the University of Michigan hospital in Ann Arbor.

The crash spread debris for more than a mile as it burned, and police today struggled to keep traffic moving about the busy airport while also closing off the crash site to all but rescue workers and federal safety officials.

Officials of the Federal Bureau of Investigation were among those examining the crash site, but their presence at airline accidents is routine and NTSB officials said today they have no reason to suspect sabotage or a bomb.

"The FBI works fast," said one federal official who asked not to be named. "If there was any reason to believe there was a bomb on that plane we would probably already know it."

Northwest has been plagued by labor problems since it merged with Republic Airlines last October. The problems have included reports of vandalism, although there is no evidence that vandalism contributed to the crash, Northwest officials said.

By noon today the plane's flight recorders, the "black boxes" that record pilot conversations and airplane performance characteristics, had been sent to federal laboratories in Washington for analysis.

NTSB officials said tonight they had early indications that the data on the flight recorders was in good shape and that it will be helpful in determining the cause of the crash.

T. Allan McArtor, the new head of the Federal Aviation Administration, was on hand along with dozens of FAA officials. He said that the flight data recorder on board the plane was a digital recorder, one of the most modern and sophisticated in the country's commercial fleet.

In 1985 two major airline accidents were attributed at least in part to failures in older versions of Pratt & Whitney JT8D engines.

In one, a twin-jet Boeing 737-200 operated by a charter subsidiary of British Airways caught fire during a takeoff in Manchester, England. The plane aborted the takeoff, but 55 of 137 passengers were killed in the fire that followed.

The second accident involved a Midwest Express Airlines twin-jet DC9 that stalled and dropped to the ground after taking off from the Milwaukee airport. All 31 people on board were killed.

A spokesman for McDonnell Douglas, the plane's manufacturer, said today that Sunday's accident was the first time a U.S.-operated MD80, introduced in 1980, had crashed. It is a stretched version of the DC9.

The JT8D engine used on the McDonnell Douglas MD80 involved in Sunday's accident is the most common commercial airliner engine in the United States.

McArtor turned aside repeated questions about overcrowded skies and airline safety. Earlier this summer, after a rash of near-collisions were reported, federal safety officials renewed criticisms of the FAA, saying that the skies were becoming dangerously crowded.

McArtor said that nothing in Sunday's accident indicated that heavy jet traffic contributed to the crash.

The NTSB convened a noon meeting of all parties involved in the investigation, including representatives from Pratt & Whitney, McDonnell Douglas, the FAA, the FBI and local law-enforcement offices. A briefing followed the meeting.

As it does in every crash investigation, the safety board divided the work into several investigative clusters that will pursue every aspect of the brief flight from the performance of the crew to the strength of the metal in the wings.

The group met again tonight and received preliminary reports from each of the investigating units.

If necessary the safety board will attempt to reassemble the entire aircraft to determine what caused the crash.

The tests, interviews and analysis involved in such an investigation often take more than a year.

Because not all the bodies have been recovered or identified, investigators today were not able to assess the physical condition of the jet as clearly as they would have liked.

"The remains of the passengers has to come first," said Lauber at the afternoon briefing at the north end of the crash site. "We can't really allow ourselves to interfere with that."

A spokesman for Pratt & Whitney said yesterday the company was tracing the history of the particular engines on the MD80 that crashed as Flight 255.

"We keep data on every engine we make, and we are looking for it right now," said Ed Cowles, a spokesman for the company. "But that jet has been a splendid performer. We have had great success with the airplane, and we don't think it would be fair to rush to conclusions about a crash until there is some solid evidence."