Investigators are still collecting evidence from the deadly explosion which occurred in a neighborhood of San Bruno, California last Thursday.
Even before they can pinpoint a cause, experts said the risks associated with aging gas pipelines are far more common than most people would think. It could be a wake up call for all of America.
The images of the initial blast from Thursday's explosion are still difficult to watch, especially for the survivors. However, it has shed light on an issue that could be far more troubling.
"I was surprised to learn the pipe under my house is 60-years-old," said San Bruno resident Dave Johnson.
The pipe in San Bruno was installed in 1956. It was laid at a time when it supported far fewer homes and families. With thousands of natural gas pipelines nationwide that fit the same bill, experts said the disaster highlights risks that communities across the country share.
One major problem with pipeline safety is just how huge the nation's natural gas network has become. There's more than 2 million miles of pipeline and only about 100 federal inspectors nationwide to make sure their owners are compliant with regulations.
Pacific Gas and Electric said the ruptured pipe had been inspected twice in the past year.
"This one, where we looked at it, historically we did not anticipate any issues," said Chris Johns, president of PG&E.
People who survived aren't so sure they'll return to their homes.
"Even if people say, 'It's ready for you to go back,' I'm not certain we want to live here," said evacuee Phil Perccio.
"It's a 30-inch pipeline," said Bob Pellegrini, whose house was destroyed. "If I'm going to rebuild I'd like to know the remaining lines are secure."
Still, an official with the National Transportation Safety Board warned this is an issue that must be addressed elsewhere.
"If this was the FAA and air travel we were talking about, I wouldn't get on a plane," said Rick Kessler, a former congressional staffer specializing in pipeline safety issues who now works for the Pipeline Safety Trust, an advocacy group based in Bellingham, Wash.