California Occupational Safety and Health Administration (Cal-OSHA) officials want to find out if a steamroller operator was safely belted in before the machine overturned and killed him.

Sixty-year-old Thomas Cadwallader from Long Beach, CA, died under a steamroller that overturned near Los Angeles International Airport recently.

It wasn’t determined how the machine rolled over but Cadwallader became trapped outside the operator’s cage, which is designed for safety. The man, who suffered head injuries, was pronounced dead at the scene.

The investigation by state officials will focus on whether Cadwallader was using a safety belt or restraint device while operating the machine.