A body boarder bled to death Friday after a shark bit off his leg and a nearby surfer pulled him to shore and called for help, authorities said.

The 20-year-old UC Santa Barbara student was attacked off a Central California beach between 9 a.m. and 9:30 a.m., prompting the closure of three beaches through the weekend, Santa Barbara County Sheriff Bill Brown told the Lompoc Record.

A friend who was on a surf board brought the man to shore at Surf Beach but the victim bled to death, Brown said.

The victim, who has been identified as Lucas McKaine Ransom, of Romoland, a city near Perris Valley in Riverside County, according to the Lompoc Record. The Sheriff’s department originally reported the victim as being from Orange County.

Authorities could not immediately determine what kind of shark attacked the student.

Surf Beach – which is 130 miles northwest of Los Angeles – is on the property of Vandenberg Air Force Base but is it open to the public. Vandenberg closed Surf Beach and adjoining Wall and Minuteman beaches for 72 hours.

A shark believed to be a great white bit a surfer’s board in 2008 but the surfer was not harmed.

In 2003, a great white shark killed Deborah Franzman, 50, as she swam at Avila Beach, about 30 miles north of Vandenberg.

Authorities have issued several warnings this year after great white shark sightings up and down the California coast. The sharks can be found in shallower waters when they give birth and they also feed on seals and sea lions.

However, attacks on humans are rare. The last fatal attack in California was in 2008, when triathlete David Martin, 66, bled to death after a great white shark bit his legs as he practiced with friends about 150 yards off of a San Diego County beach.

Randy Fry, 50, died from a great white attack in 2004 while diving off the coast of Mendocino, north of San Francisco Bay.