The explosion on TWA Flight 800 might look like a bomb, but federal investigators cautioned Friday night that it was far too early to draw conclusions.
Although some evidence suggests the possibility of a bomb, autopsies of the victims turned up no proof.
"We have a lot of scenarios we are working with," said James K. Kallstrom, the FBI's chief for the investigation. "We're not discounting anything."
Heavy seas and stormy weather slowed the wreckage recovery Friday. By Friday night, the National Transportation Safety Board had recovered less than 1 percent of the plane.
"We have the people here, we have the equipment, we have a plan, but the weather is not cooperating," said Robert Francis, the NTSB's vice chairman.
The safety board said Flight 800 appeared to be a routine flight. The Boeing 747 was in compliance with federal safety rules and maintenance records looked normal. When it departed John F. Kennedy International Airport on Wednesday, a flight computer sent an automatic message back to the airport that said the engines were operating properly.
The crew, seasoned pilots who each had more than 30 years experience, began a routine climb over the Atlantic Ocean. Thirty-one minutes and 20 seconds into the flight, as the plane reached 13,700 feet, it burst into a fireball and plunged into the water about 10 miles south of Long Island.
Rumors and unattributed reports Friday night suggested everything from a missile fired from a boat to terrorist groups claiming responsibility for the explosion. The Times of London reported a known terrorist was escorted off the plane before it left Athens, Greece, to return to New York. U.S. State Department spokeswoman Elaine McDevitt said it was "the first we've heard" of any of the reports, and couldn't confirm them.
"We really need the forensics of that aircraft to know what happened on the aircraft," Kallstrom said.
"Obviously, there was a catastrophic event on the aircraft. We all know that. So something did happen on the airplane. More than likely some explosion took place on the airplane."
Even so, the medical examiner said there was little evidence in the bodies he had examined that indicated a bomb caused the crash.
Suffolk County Medical Examiner Charles Wetli said passengers died instantly from tremendous impact but the bodies examined Friday showed no evidence of a bomb.
"We so far have no evidence of an explosion," said Wetli. "I'm not seeing anything to indicate a bomb."
If a bomb exploded in the cargo compartment beneath the cabin, it's likely wreckage would have been blown upward into the passengers' legs. But none of the bodies examined so far had that kind of damage, Wetli said.
However, Wetli said it was possible that a bomb exploded in the tail or some other section of the plane away from the passengers.
About 100 bodies had been recovered by Friday afternoon, but the other 130 victims are are believed to be under water with the main wreckage of the plane. A recovery team using sonar located a large piece of wreckage Friday, but efforts to retrieve it were delayed by bad weather and heavy seas.
Meanwhile, pathologists and dentists have been working long hours in the cramped offices of the Suffolk medical examiner to identify the victims.
There are so many bodies that they have to be stored outside in a refrigerated truck. Autopsies have gone slowly because the office has only five autopsy tables. Only five victims had been positively identified by the office Friday evening, including one man who happened to be a friend of the dentists who volunteered in the office.
The bodies were relatively intact, but most were stripped of their clothes during the explosion and free-fall from the sky. Identifying them has been difficult because families have not had time to send dental records or photographs.
A questionnaire for family members asked for information about tattoos, scars and moles. It also asked for shoe size, jewelry and, for smokers, their brand of cigarettes.
Families were also asked to send photographs of victims smiling. Teeth visible in the pictures might help dentists make a match.
Wetli said pathologists were surprised to find that the bodies appeared to be covered with bits of glitter. But the doctors discovered the glitter came from the plane's insulation.
He likened the injuries to those from a high-speed car crash, estimating that the bodies were traveling 100 mph when they struck the water.
Wetli said that for nearly all passengers, "Death occurred almost instantly."
Although Kallstrom of the FBI urged caution about jumping to conclusions about the crash, he compared it to two other terrorist bombings and urged people to call or e-mail the FBI with tips. (Phone (888) 245-4636; send e-mail tonewyorkfbi.gov)
"Anyone on the Internet anywhere in the world that has something relevant," Kallstrom said, "we'd like to hear from them."
_ Times Washington bureau chief David Dahl contributed to this report.