Surfer in Critical Condition After Shark Attack at Hawaiian Beach

— -- A surfer was in critical condition today after he was bitten by a shark at a popular beach in Hawaii.

The attack took place near Oahu's North Shore where the 25-year-old was surfing Friday, according to lifeguards. A large shark latched onto the surfer's left leg and severed it from the knee down.

Officials said a paddle-boarder came to the surfer's rescue, helping him out of the water. A nearby kayaker towed the pair to shore, where a group of Good Samaritans jumped into action, using a surfboard leash as a tourniquet to stop the bleeding.

Witness John Carper worked to keep the surfer awake as rescuers fought to keep him alive.

"They said he got his leg bit off," Carper said. "I thought 'Big, giant gash on it.' But then when we brought him back to the beach, you know, it's gone. It's gone."

The man also had cuts on the hands, a sign that he apparently fought off the shark, according to Honolulu Emergency Services spokeswoman Shayne Enright.

Medics rushed the victim to the hospital in critical condition. Chris Webster, a cousin of the surfer, said he was in good spirits before going into surgery.

"He started laughing and smiling, and he (said), 'Yeah, I got a couple of good cracks on him,'" Webster recalled.

According to witnesses, the shark was about 10 to 12 feet long, but officials said they did not the know the species or size.

Local officials warned people to stay out of the water following the attack.

This is the fifth shark attack in Hawaii so far this year. One person died following an encounter with a shark in Maui in April.

The Associated Press contributed to this report.