Clayt Casey wasn't wearing a helmet when he was hit by a truck while riding a scooter

The man killed when he ran a red light on his electric scooter on Saturday was not wearing a helmet, authorities said.

Clayt Casey, 50, of San Luis Obispo, was hit by a pickup truck and then died of a head injury at French Hospital Medical Center in San Luis Obispo, authorities said. An autopsy is scheduled for Wednesday. Authorities say that alcohol or drugs are not suspected to be involved.

Casey was riding the scooter east along Los Ranchos Road just after 10:30 a.m. when he went into the intersection at Highway 227, running the red light, according to a CHP report. Authorities say that it is not clear why he did not stop for the red light but that it did not appear “purposeful.”

Christopher S. King, 22, of Pismo Beach — driving his Isuzu pickup south, about 55 to 60 mph, along the highway — swerved left and hit his brakes, but the front of his truck struck the left side of the scooter, the CHP said.

Casey was thrown off the scooter, and struck the pickup’s windshield before landing on the ground, according to the CHP.