Officials are now investigating whether the grinder had proper guards and was properly maintained.
California workplace safety officials are investigating the death of a man at a Berkeley metal forging and tool manufacturing plant.
Thirty-year-old Ariel Munoz-Garcia died at Berkeley Forge and Tool around 10:20 p.m. Thursday when he was struck in the back of the head by a piece of metal while working on a grinding wheel.
The California Division of Occupational Safety and Health says the wheel shattered and sent metal pieces flying.
The agency is now investigating whether the grinder had proper guards and was properly maintained and what training, if any, Munoz-Garcia had received to use it.
The company declined to comment.