Two boats carrying migrants trying to get into the U.S. capsized off the coast of San Diego on Saturday night. The crash killed at least eight people.

A woman reported the accidents to 911 around 11:30 p.m. and told the dispatcher that the boat she was on was carrying eight people and the other boat had around 15 people, The Associated Press reported.

All eight individuals who died were adults, and their nationalities have not been disclosed. Their bodies have been sent to the San Diego County Medical Examiner, according to CNN.

What happened with the San Diego boats crashing?

Search and rescue efforts were paused on Sunday, due to the heavy fog and high tide that made it difficult to find people. The recovery efforts started again later in the day, but no one else was found. The boats were overturned in somewhat shallow waters near the Torrey Pines City Beach.

“That area is very hazardous, even in the daytime,” San Diego Lifeguard Chief James Gartland said at a news conference, per AP. “It has a series of sandbars and in-shore rip currents, so you can think that you can land in some sand or get to waist-high, knee-high water and think that you’re able to be safe to exit the water, but there’s long, in-shore holes. If you step into those holes, those rip currents will pull you along the shore and back out to sea.”

According to Border Patrol spokesperson Eric Lavergne, “the incident was one of the deadliest migrant smuggling operations ever in the area,” per NBC News.

Survivors may have escaped on land. The whereabouts of the caller who reported the incident is unknown. There are at least two people who are still missing, and searches are continuing for them.

“This is one of the worst maritime smuggling tragedies that I can think of,” Gartland said, per NPR.