National Transportation Safety Board investigators have been hampered by a lack of information about the section of substandard pipe where the blast occurred at a flawed weld.
Investigators say PG&E has relied on faulty or non-existent data to vouch for the safety of much of the rest of the Milpitas-San Francisco pipeline, according to a report by the San Francisco Chronicle.
Investigators have found PG&E does not know the thickness of the pipe's walls for 21 miles and doesn't know who manufactured the line or how deeply the pipe is buried.
