Feds blame gas company for deadly Mass. explosions
Federal investigators probing the deadly natural gas explosions that rocked three northern Massachusetts towns last month are blaming faulty work orders from the local utility.
The investigators say Columbia Gas failed to instruct the workers to deactivate pressure sensors when taking an old cast-iron gas main out of service. When those sensors detected a drop in gas pressure in the decommissioned main on Sept.13, the system automatically increased the pressure in the new, plastic gas main.
Within minutes, houses across Lawrence, Andover and North Andover began to explode from a buildup of natural gas.