Federal report says firefighting tactics at Maine lumber mill explosion aided the blast

The May 15 fire and explosion that killed three people, including two firefighters, originated at the base of a silo. The post Federal report says firefighting tactics at Maine lumber mill explosion aided the blast appeared first on Boston.com. PORTLAND, Maine (AP) — Firefighters who responded to a fire at a Maine lumber mill used tactics that inadvertently contributed to a massive explosion that killed three people, according to a report from federal investigators.The fire companies tried to extinguish the May 15 fire inside a silo at the Robbins Lumber mill in rural Searsmont, Maine, by injecting it with water — unaware of warnings from the manufacturer that doing so would be dangerous.The silo then blasted skyward like a rocket as flames and a shock wave from the explosion hurled workers and firefighters away.The firefighters didn’t know, the National Institute for Occupational Safety and Health wrote this month, that the silo was oxygen-limiting, a type of sealed structure that can become pressurized with combustible gases during a fire.That kind of buildup is a known hazard in oxygen-limited silos, and both the manufacturer and fire safety organizations put out firefighting guidance warning against putting water or foam into such chambers.“The document warns against spraying water or foam into the oxygen-limiting silo as it will force air in and may create a potentially explosive mixture,” the report states.

“The application of water into the silo in this incident likely entrained oxygen into the silo headspace, stirred up dust within the contents, and caused it to become suspended in an explosive concentration.”The report recommends that fire departments make sure firefighters choose appropriate tactics for silo fires and never direct water or foam into oxygen-limiting silos. It also states that more training is needed for fire departments about the hazards associated with different types of silos.The blast also injured at least 13 people and the toppling of the silo engulfed the surrounding area in fire, investigators have said. The explosion took place in the small town about 95 miles (150 kilometers) northeast of Portland and triggered a response of 299 firefighters from 46 departments across a four-county area.

It took them hours to contain the fire.Representatives for Searsmont Fire & Rescue did not return phone calls seeking comment Tuesday. The department's assistant fire chief, Wayne Woodbury, 76, died from injuries suffered in the explosion. Andrew Cross, 27, of the Morrill Volunteer Fire Department, also died.

Alden Robbins, the co-owner of the mill, died from injuries weeks later.…