More than 10 people injured after big wave slams into popular Hawaii snorkeling spot

More than ten people were injured at Sharks Cove on Oahu's North Shore when a 10-foot wave hit the tide pool – one of the island's most popular spots for diving and snorkeling – according to the Honolulu Emergency Services Department.

The incident happened on Thursday afternoon when Ocean Safety was patrolling the area by jet ski, according to Shayne Enright, spokesperson for the agency. The wave caught people "off-guard" as it washed over the rocky ledge that shelters the tide pool, dragging some out to sea and others into rocks.

A 12-year-old girl and her mother were swept out to sea and rescued by lifeguards. They were brought to shore at nearby Waimea Bay.

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Lifeguards and medical personnel treated 10 people for injuries. Three people, one in serious condition and two in stable condition, were taken to the hospital: one 18-year-old woman with a possibly head injury and lacerations and abrasions; one 16-year-old girl for lacerations; and a 22-year-old woman for lacerations and abrasions.

The cove is shallow and protected by a natural breakwater. It's a popular spot for people to snorkel or reef-walk along the sharp rocks. At the mouth of the cove, the water is deeper, with underwater caves and rock formations.

"Ocean Safety officials want to warn the public that during the high surf season on Oahu’s north shore to take extreme caution when near the shoreline," Enright said. "At anytime a wave can catch you by surprise and put your life at risk."

Oahu's North Shore is known for its powerful and ruthless waves. The island's north-facing shores are facing a high surf advisory with waves building to between 18 and 22 feet.

This article originally appeared on USA TODAY: Big wave at Sharks Cove blamed for snorkeling injuries in Hawaii