Crime & Safety
Gas Main That Caused Hayward Explosion Dated To 1940s, NTSB Investigation Shows
An explosion that injured six people and damaged multiple homes near the city of Hayward originated from a natural gas pipeline.
HAYWARD, CA — An explosion that injured six people and damaged multiple homes near the city of Hayward on Thursday originated from a natural gas pipeline installed in the 1940s, according to preliminary information released Saturday by the National Transportation Safety Board.
The National Transportation Safety Board, or NTSB, is a federal agency charged with investigating accidents including those involving pipelines. An NTSB investigative team arrived Friday at about 11:30 a.m. and reviewed the area and the pipeline.
NTSB determined that a 3/4-inch diameter steel line and 2-inch diameter steel gas main that carried natural gas to a residence in the 800 block of East Lewelling Boulevard of an unincorporated area of Alameda County were damaged during grading work for a road improvement project along the street in front of the house, the agency said.
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The six people who were injured were taken to a hospital and were in stable condition as of Friday evening, according to the Alameda County Fire Department.
The gas main was damaged by a work crew that then called PG&E to the scene to shut off the gas. But about 10 minutes after PG&E said its workers successfully shut off gas to the area, a large explosion occurred at about 9:40 a.m.
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The NTSB team will be on the scene for the next 5-7 days, NTSB spokesperson Peter C. Knudson said in an email.
During the preliminary investigation, the NTSB will establish a detailed timeline of events and notifications and test the pipeline and uncover the area around it to collect evidence. Interviews will be conducted with construction and PG&E workers, and records of work site preparation and construction practices will be reviewed.
The preliminary investigation will determine facts about the case, but a probable cause of the explosion won't be determined until the final report from the NTSB, which could take between one to two years, Knudson said.
Results of the preliminary investigation will be posted on the NTSB website www.ntsb.gov/investigations/AccidentReports/Pages/Reports.aspx.
Other investigations are being conducted by the Alameda County Fire Department, which led the response to the fire and explosion, and PG&E, according to those agencies.
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