A swimmer who was training in the ocean off San Diego County was killed by a shark on Friday.

The swimmer - who was in his late 50s - was accompanied by a group of triathletes. They were swimming at Tide Beach around 7 a.m. when all of a sudden a shark attacked him.

The identity of the unfortunate swimmer was not released yet. He was rushed to the Fletcher Cove Park lifeguard station, but the emergency treatment wasn’t enough to save his life. The man was pronounced dead at the scene, according to a statement on the Solana Beach city website.

Solana Beach is 14 miles (22.53 kilometers) northwest of San Diego.

Authorities barred swimmers from entering the water for a 17-mile stretch around the attack site. It is unknown what kind of shark it was.

However, after inspecting the injuries made by the shark on the swimmer’s thighs, San Diego County sheriff's Sgt. Randy Webb concluded that it “probably was a great white shark."

"It looks like the shark came up, bit him, and swam away," said Solana Beach Deputy Fire Chief Dismas Abelman.

Helicopters were sent to search the waters and locate the killer shark.

"The shark is still in the area. We're sure of that," Mayor Joe Kellejian said.

Shark attacks are a rarity according to a study of the University of Florida. The study shows that last year there were only 71 cases all around the world and only one has ended with the death of the victim.