that could have been a weak point. >> the fact that it occurred when it was unexpected, when there's no obvious explanation for it, there was no precursor event, there was no earthquake that we know of, there was no heavy construction in the vicinity that we know of, we don't know of any impact against the pipe, it's very mysterious, and it makes it important that we understand the cause of this. >> we've heard reports of residents saying that they smelled gas and called us beforehand. we have combed through our records for the month of september, for the nine days of september before the event, and we have not found anything in our records that would indicate that people called for that specific area. >> reporter: pg&e officials were anxious to defend themselves against reports that residents smelled gas earlier and nothing was done. >> in one instance there was a small leak at the meter, which we replaced, fixed it right away, and in the second instance there wasn't a leak found anywhere.