A polio-stricken executive at a burning rocket fuel plant chose to stay behind and call the fire department rather than flee with fellow workers, and that cost him his life, plant officials say.

Shortly after Leroy Westerfield made his telephone call, an earthquake-force explosion obliterated the Pacific Engineering Production Co. building and 11 others in the industrial complex, killing another man and injuring more than 255 people.Bruce Bernard Halker, 56, a friend of Westerfield, apparently died while he tried to coax the crippled man from the inferno, co-workers say. Westerfield, 62, had been partially paralyzed by polio since he was 19.

"If he was there, he'll stay around until everyone gets out," said Halker's wife, Roma, as she awaited word of his fate. "That plant was his whole life."

The body of Halker, vice president for operations, was found several hours after the initial blast and several that followed. Authorities spent Thursday scouring the charred rubble of the plant hoping to find a trace of the popular Westerfield, the company's controller for 28 years.

"We lost two of our very closest friends," said Fred Gibson, the plant chairman.

Production of a key fuel component for the space shuttle and U.S. military rockets was halted until manufacturers ascertain the equipment malfunction that caused the fire and explosions, which left widespread property damage throughout the Las Vegas Valley.

Plant employees, many of them wearing bandages, gathered in the community center in this city of 55,000 on Thursday to discuss the disaster and observe a moment of silence for Westerfield and Halker.

Tears welling in his eyes, Westerfield's son, Gary, said he was not surprised his father risked death to save his co-workers. "That was his style," the son said.

"His polio got so bad he could barely get around," said plant foreman Robert Thayer, a friend of nearly three decades. "It didn't affect his mind one bit."

Keith Rucker, the company's general counsel, said people at the plant tried to get Westerfield to leave when a fire spread out of control in the plant's drying room.

"It's my understanding . . . he said `no' because he had to call the fire department," Rucker said. Gary Westerfield listened to a tape of the call to fire officials. "That was my father's voice," he said.

Pacific Engineering is one of two plants in the United States that makes ammonium perchlorate, a fuel oxidizer for the space shuttle's solid rocket boosters and the military's MX, Minuteman and Titan missiles. The other is Kerr-McGee, whose plant is just a mile away from the site of Wednesday's destruction.

The explosions, the most powerful of which was registered at 3.5 on the Richter scale of ground motion, twisted steel girders like pretzels and turned some of the 40 cars parked nearby into chunks of melted metal.

Concussions from the blasts shattered windows 10 miles away in Las Vegas, jolted airliners in flight, peeled off roofs, upended cars and threw workers through walls. Broken windows and cracked foundations were common in Henderson.

Area schools closed for a week so inspectors could determine if buildings were safe. Damage estimates were still uncertain Thursday.