A pickup truck plowed through a plate-glass window at a medical clinic Friday, killing three people and injuring eight, authorities said.

The truck hurtled through the parking lot and drove as far as 30 feet into the storefront clinic, which treats work-related injuries.

"People were cut, dripping blood. I was shook up," said Jimmy Ramsey, who was leaving a coffee shop nearby. "This is stuff you see on TV."

The cause of the crash was under investigation. The truck driver was among the injured. Her name was not immediately released.

Physician's assistant Ben Martinez was working in an exam room next to where the truck crashed when he heard "a real loud bang, like an explosion."

"I thought a plane had crashed into the place," Martinez said.

Seven of the injured were listed in satisfactory condition at a hospital; the eighth was treated and released.