The water-filled crater at Glenview Drive and Earl Avenue is now raising questions about a new sewer line which was put in two years ago. It was a city project, covering a large area of San Bruno, in which aging sewer lines were replaced to address capacity and overflow issues
Part of the work involved excavating the intersection of Glenview and Earl.
"That was the final stage of the project; it had many phases which occurred over a number of years," San Bruno City Manager Connie Jackson said.
A Google Map shows the intersection and an asphalt patch, which the city's public works director says was probably the work of the sewer crew.
Fred Nesbitt lived on Earl Avenue near the intersection when the work was being done on the sewer line.
"There was a tremendous amount of pumping going on because these pulses are built in these machines and they go boom, boom, boom, all day long, it lasted about two weeks," Nesbitt said.
Nesbitt wonders if it may have contributed to the gas pipe rupture.
"Surely, you don't need to be a rocket scientist to realize it has to be a mitigating factor to this thing," he said.
NTSB investigators will only say it is one of many things they are looking at.
Among the questions are, "Who else was doing work there?" And, "Who sealed this asphalt patch shown on Google Maps just above the intersection?" and "How extensive was the dig?"
ABC7 learned that the city issued three encroachment permits in the last two years.
In 2008, landscapers repaired a curb drain. That same month, PG&E repaired a gas leak near where Thursday's explosion occurred. Last month, AT&T did some work right at ground zero.
CPUC sets up number to reported gas smell
The California Public Utilities Commission has established a toll-free number and e-mail address for anyone who noticed the smell. People can call (800) 789-0550 or send an e-mail SBFire@cpuc.ca.gov if they smelled the gas.
The NTSB has also set up a tip line for their investigation. They are interested in reports of a natural gas order or any plants dying. You can e-mail information or armature video related to this case to: firstname.lastname@example.org