OSHA investigators are looking into an explosion last Saturday at an Ohio environmental services company that killed one worker and left another badly burned.

The blast was at the Heritage WTI plant in East Liverpool, Ohio was apparently caused when a chemical reaction within a container of hazardous waste sparked a flash fire that engulfed several other nearby containers, according to WTI officials.

Service technician Thomas Bailey, 52,  was killed  in the incident. Another employee, John Bechak, is being treated at a Pittsburgh hospital.

The company said it is cooperating with OSHA. Solid waste processing at the plant was temporarily suspended because of the incident.