investigators will be looking into this microbial or roche and there was a blast in arizona at 10 years ago which had similar factors. >> take a look side-by-side at the striking similarity. the greater on the left was caused by the gas line explosion in san bruno. the crater on the right was left by the gas line explosion in new mexico in 2000. federal investigators ruled the cause of the arizona pipeline rupture was internal corrosion which can be seen in this picture. it caused a significant reduction in the pipes thickness. the corrosion was a combination of microbes and moisture. according to the san francisco chronicle pg&e told state regulators last year that they were concerned about corrosion in the section of pipe that ruptured in san bruno. a piccinni's spokesperson said microbial groschen is where and the utility has just made seven repairs for that type of groschen in the past five years. one of the findings by federal investigators and years of a blast was at the gas company failed to prevent or detect internal groschen in the pipe and that a major safety issue is the inad