California residents are being warned to stay away from wharves, piers and other shore structures as waves of 20 to 30 feet are expected to pound the northern Pacific coast for the rest of the week.

The warning from the National Weather Service came after a 150-foot section of Santa Cruz wharf collapsed during high waves on Monday and storm debris was blamed for the death of a Santa Cruz County resident on a Watsonville beach.

In Southern California, the Coast Guard announced Thursday morning that it had suspended the search for two men who went missing after a fishing trip off the coast of Palos Verdes, NBC Los Angeles reported. The wreckage of a boat believed to belong to them was discovered on Tuesday.

“Inexperienced swimmers should stay out of the water due to life-threatening surf,” the Bay Area NWS warned. “Never turn your back on the ocean.” The agency also warned of strong surf and rip currents in the Los Angeles area.

In Santa Cruz, three city workers fell into the sea but survived with only minor injuries when a large section of the pier, including a closed restaurant, collapsed and drifted away in high surf on Monday.

Nearly 20 miles farther south, at Sunset State Beach in California’s state parks, firefighters responded about 11:30 a.m. Monday to a man trapped under debris, a spokesman for the Santa Cruz County Sheriff’s Office said. The man was pronounced dead at a local hospital.

Around noon that same day, police at Marina State Beach responded to reports of an adult male who had been “overwhelmed by the high surf and swept into the water,” Marina police posted on social media. Bystanders had tried to rescue the man, but were prevented from doing so by high waves and strong currents. As of Tuesday, the missing person had not been found, police said.

“It’s total chaos,” Santa Cruz resident Bud Freitas told the Los Angeles Times, describing the impact of the waves. “I just drove through the south side of town and the beaches are all torn up. It looks like a bomb exploded.”