PG&E spokesperson Tamar Sarkissian said a shut-off valve to one of the buildings in the Town Centre Commons in the 1200 block of Central Ave. broke while being serviced at about 12:30 p.m. Crews dug at least three holes in the parking lot in search of the 1 1/4-inch line, but had been unable to find it.
An engine from the East Contra Costa Fire Protection District stood by as a precaution.
"We've been having a little bit of difficulty locating that line," Sarkissian said at about 4:30 p.m. "The site is safe, between the evacuations and the fire department being on hand. We know this is a big inconvenience for people and we apologize for that. We're just ensuring everyone stays safe."
ECCFPD Captain Robert Ruddick said firefighters and police helped evacuate the buildings, most of which were empty in the middle of the work day. Parts of three buildings were evacuated.
Battallion Chief Jeff Burris said architectural plans and construction documents were compared in an effort to locate the line.
No injuries were reported. Sarkissian said repairs had been made and crews were re-lighting pilot lights in 14 apartments impacted by the temporary shut-off.