SAN FRANCISCO (AP) — A group of San Francisco neighbors said they had to do something to make their street safe. Their answer? Some giant rocks.

Fed up with what they see as the city's failure to combat homelessness and rampant drug use, the neighbors had boulders delivered to their sidewalk to block people from pitching tents on their street.

That started a fight that shows the frustration with an unprecedented homelessness crisis in California. Cities are struggling to address the lack of affordable housing and a growing number of homeless encampments that are popping up on city streets, som...