Surging waves collapsed a seaside sidewalk in Pacifica on Sunday, as the latest in a string of winter storms pushed onshore.

Waves expected to reach 19 feet high pounded the shore and eroded the ground beneath of a stretch of sidewalk along Beach Boulevard, between Santa Maria Avenue and Salada Avenue. Workers with backhoes brought in boulders to shore up the sidewalk and adjacent road during the afternoon. But by early evening, city officials were still warning drivers to avoid the area.