A federal official investigating the deadly home explosion in Rancho Cordova said Monday the neighborhood should have been evacuated before the blast. A gas leak was reported, though the call logs are under scrutiny and probably won’t be made public until the end of the investigation, which could take as long as 6 months to a year. A Pacific Gas & Electric worker was at the scene when the home exploded on Christmas Eve.

Karl Gunther, who is investigating the blast for the National Transportation Safety Board, said at a news conference Monday if someone can smell gas, the entire neighborhood is typically evacuated. Gunther called the leak “very, very big” and said the location of the explosion was thought to be about 30 feet from the driveway of the home that exploded. The trouble area has been identified as a coupling on a pipe. It is still not clear what sparked the explosion or what caused the coupling to fail.

PG&E spokesman Jeff Smith said the utility company will be looking very closely at the procedures it followed in the case.”We’re always looking for ways we can improve our process,” he said.  PG&E had said earlier that an evacuation of the neighborhood was not warranted.