Short answer, it's within the purview assigned to the NTSB. Longer answer: pipelines are a form of bulk material transport and are a non-trivial bit of transpo

Short answer, it's within the purview assigned to the NTSB. Longer answer: pipelines are a form of bulk material transport and are a non-trivial bit of transportation infrastructure. The NTSB seems like not too bad a place to assign accident investigation for pipeline accidents. https://en.wikipedia.org/wiki/National_Transportation_Safety_Board https://en.wikipedia.org/wiki/National_Transportation_Safety...