A tree removal company had been working to dig up a tree stump along the sidewalk on the corner of Fourth Street West and Bettencourt Street when the crew damaged the 2-inch steel distribution line, Sonoma Valley Fire Division Chief Bob Norrbom said.
Authorities received a report of the leak at 11:19 a.m. and a shelter in place was instituted for a two-block radius around the intersection, an area that includes Sonoma Valley Hospital, Norrbom said.
Because the emergency room was within the affected area, ambulances were diverted to nearby hospitals, he said.
PG&E was notified at about 11:25 a.m., and a crew was on scene by about noon, utility spokeswoman Brandi Ehlers said.
The repair crew stopped the flow of gas at about 2 p.m. and was still working on repairs as of 3:30 p.m., Ehlers said. Only one residential customer was affected.