Gas Line Explodes in California

Last Thursday in San Bruno, California a gas line exploded into a big fireball.  The explosion left four dead, three missing and 60 injured.  The damage is an estimated $65 million from homes and construction.  The cause of the gas line leak is said to be from work near a local sewer back in 2008 near the gas line.  After further research it is not thought the sewer problem had anything to do with it, however it is still suspect.  One other reason could be that the pipe was installed in1948 and had a chance to rupture.  That is a big current news issue.