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Five people were injured and two were hospitalized during Friday's second round of the U.S. Open at Pebble Beach when a golf cart rolled into spectators, according to Golfweek's Bill Speros.

"Unfortunately, during today's second round, there was an incident involving a golf cart on the 16th hole that resulted in three spectators and a vendor being injured and requiring medical condition," the USGA said in a statement provided to Speros. "We will continue to monitor their conditions."

GOLF.com's Dylan Dethier described what happened:

"At around 10:20 a.m. local time, a vendor was delivering several boxes in a golf cart near a concession stand on No. 16 at Pebble Beach. As the vendor got out of the cart, one of the boxes fell onto the accelerator, causing the golf cart to start moving, according to eyewitnesses.

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"'We were standing in the concession line on the 16th hole when all of a sudden there was a runaway cart and one guy running after it, then a bunch of people running after it,' Georgie Salant told GOLF.com. She was standing by the concessions at the time. 'It was actually coming straight for the concession line and then it turned, just on its own, and it didn’t stop! It started driving in circles. It ran over like, five people.'"

The Salinas Californian's Joe Szydlowski relayed information on those injured: an 82-year-old man from Modesto, California; a 58-year-old man from Modesto, California; a 58-year-old woman from Carmel, California; a 25-year-old man from Highland, Texas; a 43-year-old man from West Jordan, Utah.

According to Szydlowski, the California Highway Patrol is investigating.