Riverside County authorities Wednesday identified the man killed in an explosion at a tanker truck company in Corona as Samuel Enciso, 51, of Santa Fe Springs. 

Enciso was welding a petroleum tanker truck Tuesday inside National Distribution Services in the 300 block of North Grant Avenue. About six to 10 employees were working on the truck. 

For reasons still unknown, and being investigated by the California Occupational Safety and Health Administration, a blast occurred about 1:50 p.m. 

Enciso died at the scene. A second man, who hasn't been identified, was taken to a hospital in critical condition.

No other employees were hurt, and the business was evacuated. The explosion was contained to the facility, located in a residential area, and didn't require the evacuation of nearby homes. 

Cal/OSHA spokesman Greg Siggins said the investigation into the incident could take up to six months to complete. Those results would determine whether there were any workplace safety violations.