Investigators Seeking Cause of Munitions Blast

Investigators continued Wednesday to probe the cause of a blast at a Chino Hills ordnance plant that injured 11 workers, including an Ontario woman who lost an arm and was hospitalized in critical condition.

Meanwhile, state authorities disclosed that the Aerojet Ordnance plant has been the subject of five previous investigations after accidents in the past 12 years, including a 1986 incident that company officials say resulted in a fatality.

That accident and another resulted in fines of $900 against Aerojet for violations deemed serious under state codes, said a spokesman for the California Occupational Safety and Health Administration. Aerojet manufactures artillery shells for the military.

The explosion Tuesday afternoon apparently was caused by a malfunction of a loading rack on which detonating devices are installed in the artillery shells, according to Chino Hills fire officials.

But Aerojet spokeswoman Edie Cartwright said Wednesday that the theory is only speculation and the accident remains under investigation by the company and federal safety officials.

Hospitalized in critical but stable condition Wednesday at San Bernardino County Medical Center was Otilia Belmontes, 36, whose arm was severed by the blast. A hospital spokeswoman said she was in surgery for nearly three hours Tuesday night.

The other injured workers, most of whom suffered shrapnel wounds and eardrum damage, were treated at area hospitals and released, Cartwright said.

Belmontes, of Ontario, was employed as an ordnance assembler and had worked at the plant since 1979. Cartwright could not say what Belmontes was doing when the explosion occurred, or how many people were in the area.

Cal/OSHA spokesman Richard Stephens said Wednesday that state records do not indicate the number and nature of injuries in the five previous incidents. Cartwright said the only serious accident among them was the 1986 fatality, which she blamed on an employee improperly handling explosives.

In that accident, on which Cal/OSHA no longer maintains a file, Aerojet was fined $600.