The gas line that exploded and killed at least four people in San Bruno last week was a 30 inch transmission line. Those are the fatter pipes that run straight from the source of natural gas. PG&E says they're inspected regularly.
"This particular section of transmission line was surveyed for leaks in March of this year, March of 2010."
That's Matt Mauman, a spokesman for PG&E. He says the California Public Utilities Commission has ordered PG&E to inspect its pipelines again. There are 64-hundred miles of transmission pipelines around the state, plus 42-thousand miles of smaller distribution pipes.
"We know our customers do have questions and we hope that it will reassure our customers that we have once again checked our gas lines throughout California."
Officials still say they have no idea what caused the explosion. PG&E has also promised 100 million dollars to San Bruno to aid with recovery. Three million of that has already been delivered.