The National Institute for Occupational Safety and Health recommends reviewing operating guidelines for silos and combustibles after two S.D. volunteer firefighters were killed in a silo explosion.
Sunset Colony Firefighters Jacob Waldner, 20, and William Waldner, 22, were trying to extinguish a fire in a coal silo. After removing 80 of the 100 tons of coal, Jacob and William started applying water through an access hatch on top of the silo when an explosion occurred, killing the cousins. A third firefighter, one of the cousin's father, was seriously injured, according to NIOSH's report.
After crews removed most of the coal, they deemed the remaining 20 tons to be too hot to transport and decided to extinguish the fire the top of the silo.
Jacob and William were brought to the roof of the 50-foot silo with an aerial lift and flowed water on the hot coals for only four minutes when the explosion occurred. The explosion was strong enough that the roof of the silo that Jacob and William were standing on was blown into the air, crushing the pair.
Although fellow firefighters immediately rushed to help, Jacob and William were later pronounced dead at the hospital.
Standard Operating Guidelines
Investigators say departments should devise standard operating guidelines for structure fires that involve silos. Silos can be peculiar to approach because they are often oxygen-limiting, making fires more volatile and unpredictable when oxygen is introduced or reduced, like in the case of Jacob and William fighting the blaze from an overhead open hatch.
The contents also present an extra hazard. The coal, in this instance, can self-combust and release gases and fumes that are highly explosive.
The use of water and traditional firefighting foam is also discouraged by officials, who say the best method to fighting a coal fire is using a micelle encapsulator fire-extinguishing agent, such as a F-500.
When dealing with such a specialized type of fire attack with no standard plan, the report encourages crews to seek expert help in the matter.
NIOSH is also recommending departments train their crews on how to fight silo fires.
Silos can come in either an oxygen-limiting or traditional style, and firefighters should know the difference when attacking a blaze.
The NIOSH report says that the two firefighters may have introduced oxygen to an oxygen-limited silo, which is known to trigger backdrafts or explosions.
Investigators say firefighters should avoid going to the top of silos to fight flames and should establish a collapse zone in case the silo loses stability in the fire.
While protective gear may not have saved Jacob's and Williams' lives, they were not wearing any during the incident, which NIOSH warns against.