California's acting governor, Lt. Governor Abel Maldonado, called the timeline for an investigation into the rupture of a natural gas pipeline in San Bruno "unacceptable."
The explosion and fire killed seven people, injured dozens more and destroyed nearly 40 homes.
National Transportation Safety Board members investigating the disaster said it will take at least a year to complete their investigation.
Lt. Governor Abel Maldonado said California can't wait that long. He called on the Public Utilities Commission to immediately ensure the safety of California's natural gas transmission lines.
Pipeline was "high risk"
Federal and state investigators say the section of natural gas pipeline that ruptured and exploded in a deadly fireball near San Francisco had been categorized as high risk because it ran through a highly populated area.
Police say five people are still missing. They also say remains have been found but aren't elaborating, leaving unclear whether they are those of a victim or victims already accounted for.
Documents show that the utility submitted paperwork to regulators saying a section of the gas line — about two and half miles from the blast — was within "the top 100 highest risk line sections" in its service territory.
The federal pipeline agency classified the line as a "high consequence area" requiring more stringent inspections.
Nationwide, only about 7 percent of gas lines have that classification.
In a letter Saturday to Public Utilities Commission president Michael Peevy, Maldonado asked the PUC to:
· Ensure the safety of San Bruno properties.
· Order the Pacific Gas and Electric Company to survey the company's leak response times and the effectiveness of their responses to reported leaks.
· Survey gas transmission lines in densely populated areas.
· Inspect all three transmission lines that run through San Mateo County.
· Identify and replace manual valves with automated valves that would shut off when pressure in the line increases to dangerous levels.
· Order the Pacific Gas and Electric Company to inspect all transmission lines statewide for leaks.
Maldonado called the explosion in San Bruno "a horrific tragedy."
"We cannot ever let this happen again."
The Associated Press contributed to this report