A freak lightning storm that struck Los Angeles on Sunday took beachgoers by surprise, resulting in one fatality and eight injuries, according to local reports.

Innocent beachgoers were just enjoying an afternoon in the sun when out of nowhere a lightning storm materialized above them on Venice Beach of southern California, officials said.

Although the storm only lasted 15 minutes, it was enough time to kill 20-year-old Nick Fagnano, who was pulled from the water as lightning bolts continued to streak the sky above, and injure eight people, who were later rushed to the hospital. One of them, as of Monday, was in critical condition.

"I'm not a scientist, but when lightning hits water, water is a conductor of electricity. So anybody within any region around that lightning bolt was going to feel an electrical shock and probably be knocked unconscious," Fanano's uncle, Dan Shanahan, told the Los Angeles Times.

An exact cause of death for Fagnano had yet to be determined Monday pending an autopsy.

In a separate incident on Catalina Island, off the coast of Los Angeles, lightning struck a man and set off brush fires.

The 57 year-old victim did not suffer threatening injuries, police told The Times.

The extremely rare and bizarre weather event occurred after an intense high-pressure system pulled an unusual mass of hot, moist air up from Mexico and the Gulf of California to the coastal areas, creating unstable atmospheric conditions.

According to Bill Patzert, a climatologist with the NASA Jet Propulsion Laboratory, those air masses normally travel no farther west than the high desert and mountains.

"This was a sneak attack that took everybody by surprise," he told The Times. "Coastal Southern California is virtually lightning-proof. Because it's so unusual, people are not sensitized to the dangers."

The West Coast has the lowest incidence of lightning strikes in the nation - the odds of being hit are 1 in 7.5 million in California compared to 1 in 600,000 in Florida, the nation's "lightning champion."

Patzert said the unusual conditions would continue through Wednesday and advised people to follow the National Weather Service's warning: "When thunder roars, go indoors."

A National Weather Service analysis of lightning deaths from 2006 to 2013 found that most fatalities occurred during leisure activities, and most victims were males between ages 20 and 29.