Worker Killed, Another Hurt in Explosion at Plant : Blast: Man dies instantly operating machine at pharmaceutical factory in Santa Fe Springs.

One man was killed and a co-worker was slightly injured Thursday when an explosion damaged a pharmaceutical plant in Santa Fe Springs that manufactures aspirin and other products, authorities said.

The dead man, whose identity has not been disclosed, was killed instantly by the blast shortly after 1 p.m. at KM Lee Laboratories in the 10000 block of Shoemaker Avenue in Santa Fe Springs, 14 miles southeast of downtown Los Angeles, officials said.

A KM Lee official said the injured co-worker, 17, was overcome by smoke when he tried to rescue the man killed by the blast. The injured worker, whose identity also was withheld, was reported in stable condition at Norwalk Community Hospital.

Four other employees in the plant at the time were not injured, KM Lee production manager Steve Totten said. He said the man who died was operating a machine that grinds up old, unsold tablets when the explosion occurred.

Investigators said the cause of the explosion was not known. Fire officials noted that dust in the air at the time of the blast might have been ignited by a spark.

The force of the explosion buckled the plant’s sliding metal doors, but no other exterior damage was visible.

Employees of nearby businesses were briefly evacuated while hazardous materials specialists examined the building for dangerous chemicals.

Ron Melville, sales manager for an equipment rental store across the street said the explosion sounded like a “very close and very intense sonic boom.” Melville said a thin white cloud could be seen coming from the building after the explosion.

Alex Marrujo, a purchasing clerk for another nearby firm, said he thought an earthquake had rocked his desk. When he went outside to investigate, he saw three obviously shaken KM Lee employees in tears over the death of their co-worker.