A driver died and at least five people were hurt as a vehicle crashed Tuesday evening into an Austin, Texas, medical center emergency room, the facility’s chief medical officer said.

The crash “does not appear to be an intentional act,” city police said on social media, citing preliminary information. “There is no threat to the general public.”

Stephen Hughes was at St. David’s North Austin Medical Center waiting for his wife to come out of surgery when he heard a loud bang, then realized a vehicle had crashed into the building.

“At first I thought it was an explosion,” he told CNN. “Then I heard screaming and saw the smoke coming from the ER entrance.”

People ran through the emergency room lobby as the vehicle’s tires spun with a screeching sound, video of the panicked scene shows. The area was cleared of bystanders, and hospital staff quickly began tending to the injured, Hughes said.

A person in the car was extricated and given CPR before dying at the scene, Thayer Smith of the Austin Fire Department said. It was the driver, the hospital’s Chief Medical Officer Peter DeYoung said.

Four victims – including an adult and a child in critical condition – were taken to other hospitals, Austin-Travis County Emergency Medical Services officials said; the child had life-threatening injuries, and the adult’s injuries could be life-threatening. One patient was admitted to St. David’s hospital, DeYoung said.

Eight hospital patients who were not hurt in the crash were transferred to other hospitals, DeYoung said. Austin-Travis County EMS officials earlier had said in a Facebook post at least 11 people were injured after the crash.

Damage to the building was minor, DeYoung said, but the hospital only took emergency room walk-ins Tuesday night as ambulances were directed to other facilities.