NTSB Hearing Documents: 'How Come You Don't Weld It On the Inside?'

The NTSB released thousands of pages of documents today related to its ongoing investigation into the Sept. 9 gas pipeline explosion in the Crestmoor neighborhood. Over the next few days, we'll be highlighting some of the most interesting facts from these documents. 

One of those is a transcript of an interview (see attached) National Transporation Safety Board investigators conducted with a retired PG&E welder who worked on Line 132 when it was relocated to the Crestmoor neighborhood in 1956. In the interview, he provided some insight into how the pipe was welded and even explained all the objects that used to be found in the pipes—debris, old lunches, jackets, wild pigs—when he would have to crawl through them for inspection. 

Investigators are looking into the on Line 132 as a possible cause of the explosion. Some segments of the pipe were only welded from outside of the pipe, which has raised some concerns among investigators about the welding practices and standards that were used on the gas transmission line when it was originally installed.