Story highlights The great white shark was at least 15 feet long, officials say

Authorities release a photo showing teeth marks on a surf board

39-year-old Francisco Javier Solorio died in the attack

Four friends were riding waves off Surf Beach at Vandenberg Air Force Base

A great white shark was responsible for killing a surfer in Southern California this week, authorities said Wednesday.

Officials released a photo showing marks from the shark's teeth on the bottom of a surf board.

"The shark in this tragic incident has been positively identified as a 15- to 16-foot great white shark," the Santa Barbara Sheriff's Office said in a statement.

A shark researcher made the determination after examining the body of Francisco Javier Solorio Jr., who was bitten on the left side of his upper torso Tuesday, the statement said.

The shark attacked when the 39-year-old was riding waves with three friends off a beach at Vandenberg Air Force Base.

One of the friends saw the attack, swam over and pulled Solorio out of the water and onto the beach, Sgt. Mark Williams with the sheriff's office said. The friend gave him first aid while another called for help, he said.

Paramedics pronounced Solorio dead at the scene, the sheriff's office said.

In October 2010, another shark attack killed a 19-year-old college student off the same beach at Vandenberg.

That shark, described as being 14 to 20 feet, bit off the left leg of Lucas McKaine Ransom of Romoland, California, while he was Boogie Boarding with a 20-year-old male friend, authorities said.

Ransom was a junior at University of California at Santa Barbara and was majoring in chemical engineering.

Surf Beach is one of three that sit on the coastal military base and is the only one open to the public, a military spokesman said Tuesday.

Solorio, who was from Orcutt, just two miles from Vandenberg, wasn't affiliated with the military base, said a Vandenberg spokeswoman.