Five people were injured at the U.S. Open when one of several boxes being loaded onto a golf cart fell onto the accelerator and sent the cart into spectators.

The California Highway Patrol says a vendor parked the cart near the 16th hole Friday at Pebble Beach and was walking away when a box fell onto the gas pedal, moving it forward. It struck four spectators and the vendor before it was brought under control.

The Monterey Herald says two victims were taken by ambulance to Community Hospital of the Monterey Peninsula. Their names were not released, and the hospital said it could not give out information on injuries over the phone.

The USGA acknowledged the accident in a statement and that three spectators and a vendor required medical treatment.