Follow CBSMIAMI.COM: Facebook | Twitter

KEY BISCAYNE (CBSMiami) — Bruises and tire marks are visible on a man’s body moments after he and two others were run over by a Miami-Dade County truck.

“I heard a woman screaming,” said a witness and regular at the beach, who asked to remain unidentified.

A Miami-Dade County Parks and Recreation officer, in his county truck, a Ford F-150, turned onto the sand and drove over the beach-goers’ legs, police said.

“They had bruises on their legs, on their arms, one of them almost passed out on the sand,” he said.

The victims, between 16 and 20 years old, were lounging in the sand, between towers 8 and 9 at about 5:30 Friday afternoon, when they were run over.

Tire marks were still visible in the sand before the sun set.

The driver was upset when he got out of the vehicle, said the witness, with both hands on his head in disbelief.

A CBS4 viewer said the driver called rescue crews. Officials said the employee was doing his job.

“It’s standard operating procedure for a county security guard to let folks who are using the parks know that it is closing and it’s unfortunate what took place, obviously, but the matter is under investigation,” said Miami-Dade County Communications Director Mike Hernandez.

While the beach-goers were fortunate to walk away with only minor injuries, some are wondering why trucks are allowed on the beach, aside from emergencies.

“They can use motorcycles, they can use other types of vehicles,” said the witness. “These are F-150 trucks. They’re heavy trucks.”