Hanalei fireman Tim Terrazas holds the surfboard Bethany Hamilton was paddling on when she was attacked by a shark Friday morning off Makua Beach, Kauai.

A nationally-ranked,13-year-old amateur surfing star from Princeville lost her left arm from just below the shoulder in a shark attack while surfing off Makua Beach on the North Shore Friday morning.

She was lying on her surfboard in "crystal clear" water about 1,200 feet offshore when the shark attack occurred at about 7:30 a.m., Kaua'i Fire Department Battalion Chief Bob Kaden said during a news conference held at the county's Emergency Operations Center in Lihu'e.

When the attack occurred, Hamilton was surfing with her best friend, Alana Blanchard, also 13 years of age, and Blanchard's father, Holt, and brother Byron, a family friend said. Holt Blanchard was ten feet from Hamilton when he heard her yell out "shark, shark," Kaden said. "He thought she was fooling around, kidding and looked over and her arm was gone," Kaden said.

Kaden said he didn't know what type of shark attacked Hamilton, but it appeared to be a large one. "Our people estimated the bite mark on the board to be about 16 inches long and about 8 inches wide," Kaden said. The size of the bite suggested the shark ranged from 12 to 15 feet, Kaden said.