A shark bite victim pulled from the ocean off South Florida died from massive blood loss and was likely bitten by just one shark, authorities said Friday.

Stephen Schafer, 38, was kiteboarding about a quarter-mile offshore in Stuart, 100 miles north of Miami, when he went into the water and was surrounded by at least three sharks, according to the lifeguard who pulled him from the ocean.

Schafer died a short time later at a hospital.

Dr. Linda O'Neil, an associate medical examiner in Martin County, said Friday he died from blood loss.

She said he suffered two shark bites, most likely from the same animal. It was not clear exactly what type of shark bit him.

O'Neil said Schafer was bitten on the buttocks and on the right thigh. His right hand was also wounded, but that apparently happened when the shark bit his thigh.

"It looks like the shark hit his leg and he put his hand down there and that became part of the same bite," O'Neil said.

The thigh wound, which severed branches of the femoral artery, was fatal.

"That was the more significant wound and would have caused death even without that bite to the buttocks," O'Neil said.

It was the first deadly shark attack in Florida in five years. The last was in 2005 off the Panhandle, where a 14-year-old Louisiana girl was attacked while swimming about 100 yards off shore.

The International Shark Attack File at the University of Florida's Museum of Natural History lists 1,032 documented shark attacks in the U.S. since 1690. Fifty were fatal. Florida leads the world in the number of shark attacks annually.