AYER, Mass. (AP) - An explosion at a Massachusetts manufacturing facility has killed one worker and injured another.
Officials say the man was an employee at Advanced Vacuum Systems in Ayer, about 40 miles (64 kilometers) northwest of Boston.
The Middlesex District Attorney’s office says its investigation suggests the explosion was the result of a pressure vessel malfunction.
The workers have not been identified.
Two firefighters also sustained minor injuries.
The investigation is ongoing. The federal Occupational Health and Safety Administration is conducting a separate investigation.
Advanced Vacuum Systems manufactures custom vacuum and pressure furnaces.
Please read our comment policy before commenting.