The blaze that turned the MGM Grand Hotel into a smoldering death trap for 83 people and injured at least 500 others Friday was caused by a combination of elements that violated no laws and conceivably could exist at any typical big hotel in the country, according to the initial findings of investigators sifting through the sodden black rubble.

The 26-floor pleasure palace, one of the largest hotels in the world, had no smoke detectors, no automatic alarm system and automatic sprinklers in only a few scattered areas. The Clark County fire code did not require such safeguards seven years ago when the hotel was built.

The manual alarms on each floor were useless, officials said, because the fire apparently demolished the alarm amplifiers, located in the basement, within the first moments.

Officials said they have found no evidence of code violations or illegality.

Though fire officials have long favored more stringent safety provisions, efforts to force older hotels to "retrofit" have failed in courts around the country, said Clark County Fire Chief Roy Parrish.

The fire began in electrical wiring over a delicatessen restaurant at the east end of the huge casino, according to officials. The fire apparently smoldered for an unknown number of hours before it found fresh oxygen and burst into a fireball, which raced with a rolling motion known as "flashover," up and across the "eye in the sky" catwalk above the gaming tables from which the casino staff watches the players.

The flames collapsed the false ceiling and as they blossomed downward, air currents swept them back through the casino like a blowtorch.

"The fire exploded with such force, it knocked one employe down," Parrish said.

"The fire left two victims frozen in their tracks by slot machines, dead, according to one witness who toured the building after the fire was extinguished. The fire also caused an electonic keno board to explode.

The fire was fed by the mostly plastic, glittery trappings of the casino, which stretched half again the length of a football field. Gambling chips, fancy flocked wallpaper, furniture, fabrics, and other interior decorating material contributed to the fatal character of the fire, officials said.

Most of the dead were killed not by flames but by poisonous gases, including chlorine and cyanide created by a critiacal heat build on those synthetic materials. The gases were then carried along in the billowing, acrid black smoke.

The position of elevator shafts, air-conditioning equipment and air ducts -- all located near the casino and restaurant -- helped to rocket the poisonous smoke toward the upper floors, officials said.

"We think the elevator shafts created a piston action that sucked the smoke up," said Deputy Fire Chief John Pappageorge. "Then when it got up to the top, it had no place to go and started back down." Asked about the safety of the materials used in the construction of the hotel, Parrish said, "You got plastics in every building you enter nowadays. This was no different."

The most unusual aspect of this fire, according to Clark County Coroner Otta Ravenholt, was the fact that most of the victims (about 60) were found on the upper floors, 19 to 24, and about 15 on the first floor, but virtually none on the floors in between.

Most of the victims on the upper floors died beside open windows, slumped in a sitting position, as if they had been awaiting rescue. There did not appear to be much evidence of struggle.

Some people apparently were killed after they broke open the windows to get fresh air, but smoke came pouring through instead.

Autopsies as well as studies of survivors will reveal more about the nature of the deadly gases that filled the MGM, Ravenholt said.

As he talked, members of his staff went about the business of trying to identify the dead, who lay on metal carts around the morgue. They cataloged their belongings and piled them on the victim's chests -- small piles of cash, watches, personal photos, credit cards and matchbooks from hotels along the Strip where they had reveled on what turned out to be their last evening.

The staff had identified 71 of the dead by late afternoon today, Ravenholt said. The next-of-kin had begun to gather, pale-faced and red-eyed, in the outer lobby.

Ten of the bodies, burned beyond recognition, will take longer to identify, he said. The others are being identified based on the contents of purses or wallets, to the extent possible, rather than waiting for dental records and fingerprint matches, he said. This method has already led to the erroneous identification of one woman, he added.

Survivors of the blaze were scattered at five hospitals. Relatives and friends could find them by consulting a list compiled by the hotel, based on forms filled out by survivors and other persons, officials said.

The functioning of fire doors also raised questions about safety in the aftermath of the fire Friday. Some doors apparently had locked automatically, as they were designed to do, trapping people in smoke-filled stairwells as they tried to escape. Other fire doors reportedly were propped open by fleeing guests, allowing the fatal smoke to spread.

One system that apparently functioned smoothly in the first panicky minutes after the fire was discovered was the drill for saving the cash. Casino dealers and other employes managed to scoop up most of the cash and deposit it in a fireproof vault, according to a security guard.

There was more than a million dollars in cash in the casino cage when the fire broke out, according to the Las Vegas Sun.

A sprinkler system at the east end of the casino worked properly and ultimately helped put out the fire, the fire chief said. Other sprinkler systems apparently did not work.

The MGM Grand, built in 1972-73, conformed to the 1970 fire safety laws in effect at the time. When the rules were stiffened last year to require smoke detectors and sprinklers, existing hotels were "grandfathered" so that they did not have to conform.

Nevada Gov. Robert List, meanwhile, announced he would appoint a blue ribbon panel to reassess the state's building and safety codes. Some Nevada lawmakers, however, said they think those standards are strict enough already.