County OES officials said the gas main was ruptured in the course of road work being done in the area.
A .75-inch steel pipe was damaged and began leaking gas around 10:45 a.m. in the 300 block of Fifth Avenue, Pacific Gas and Electric Co. spokesman Joe Molica said.
Residents in the 200 and 300 blocks of Fifth Avenue were advised to stay indoors while PG&E crews repaired the gas main.
Four customers lost gas service during that time. Service was expected to be restored by 1:30 p.m., Molica said.