Blast makes testing all gas lines crucial

In the wake of the deadly and destructive natural gas explosion in San Bruno, the state was right to order a thorough and diligent examination of the giant web of natural gas lines that supply California homes and businesses.

The underground line that fueled Thursday night's fireball was installed in 1948, likely similar in age to many of the buried lines on which we depend in Marin.

Thursday's explosion created a crater 167 feet long by 26 feet wide in the middle of a typical subdivision.

Four people were killed. As of Monday, four days later, four people remained missing. At least 60 people were injured. In just a few hours, nearly 50 homes were destroyed, leaving a swath of ash and scorched chimneys along curving suburban streets that until Thursday night had been lined with homes.

The San Bruno neighborhood is similar to the many baby-boom era subdivisions that are so common in Marin.

PG&E has promised its full cooperation. The utility's leadership must back up that promise with swift action.

Public trust in the power giant already has taken a beating after PG&E spent millions on June's Proposition 16, a ballot measure narrowly rejected by voters that was a brazen attempt to strengthen its monopolistic hold on Northern and Central California's power market. PG&E's trust problem also has raised questions about its SmartMeter program.

Public safety should be one of PG&E's highest priorities.

Marin gets its natural gas through high-pressure lines similar to those in San Bruno. They are made of steel, cast iron or plastic and run through populated areas of the county. There are 51 miles of buried gas lines in Marin.

PG&E says it inspected the San Bruno line in March. The company had plans to replace that line with a new, smaller one.

On Thursday night, the 62-year-old line apparently burst.

Just as earthquakes and wild fires have led to changes, it is likely that this tragedy will bring about many reforms in terms of pipeline maintenance and location, emergency preparedness and strategies and greater public awareness.

As PG&E evaluates its huge web of lines, its decisions regarding their safety must err on the side of caution. State and local officials should be kept advised on the tests and the results.

San Bruno illustrates the growing problem posed by so much of our aging infrastructure. Some issues simply can't wait - they involve public safety. These pipelines are one of them.