there were also children playing on a grassy area near the median. Martin Quijano, 25, of Half Moon Bay, received a phone call from a friend about 4 a.m. and immediately got into his car and drove toward Skyline Boulevard. At first, he was scared, but in the end, he was just anxious to get home.
O'Callahan said he was surprised that people had collected there. The county had sent out word of the evacuation centers set up at schools, which were closed for the day as a safety precaution, on higher ground along the coast. But he said his office adapted to the situation by providing portable toilets and food.
"People got out of the inundation zone, that's good," he said. "Lesson learned for us, we will be ready for that (in the future)."
Gov. Jerry Brown late Friday declared a state of emergency for San Mateo County, along with Del Norte, Humboldt and Santa Cruz counties.
Brad Alexander, spokesman for the California Emergency Management Agency, said the declaration will help responders overcome legal issues. For instance, it gives them the right to go on private property as part of the response. It also frees up funding and allows the state to ask for federal resources.
"It cuts a lot of the red tape," Alexander said.
As in the last significant tsunami warning, in February 2010, San Mateo County fared better than other coastal California communities.
Dozens of boats were destroyed in Crescent City and a man seeking photos of the tsunami was pulled out to sea near the mouth of the Klamath River. Santa Cruz also saw a dock destroyed and more than 30 boats break free from their moorings, several of them sinking and a number sustaining serious damage.
Although emergency officials reminded residents to avoid the coastline, there were plenty of onlookers trying to catch a glimpse of the waves.
As spectators gathered near the Pacifica boardwalk, a couple walking their dog along the sea wall said they weren't frightened by the reports and had no intention of evacuating. The waves were scarcely bigger than on a typical day. The couple was dubious of news and weather reports.
"They also told us it was going to snow a few weeks ago," said Matt Jetty, 31, of Pacifica, who was with his wife Meghan, 27.
Mark Johnsson, a geologist from the California Coastal Commission, said onlookers were probably expecting movie-style waves.
"Hollywood made it seem like (tsunamis are) big, huge, crashing waves," Johnsson said as he stood monitoring the waves in Pacifica. "But it's more just a big, gradual inundation." Visually, it is like a carpet rather than a wall of water, he said.
Johnsson was out from 8 to 9 a.m. In that hour, he said he had seen two tsunami waves. As he spoke, a man hopped over the sea wall and onto the beach perpendicular to Pacifica Pier.
"I wouldn't be walking on that beach right now. No way." Johnsson said, looking down at the tracks the man left while walking in the wet sand.
A strong earthquake
A sudden rise or fall of the ocean tide
A loud, roaring sound (like an airplane or a train) coming from the ocean
What to do if you see these signs:
Move inland to higher ground or into a tall building immediately and stay there
Turn on your radio or television to learn if there is a tsunami warning
Stay away from the beach until officials issue the all-clear, as the waves can hit more than once
Source: National Oceanic and Atmospheric Administration