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.