NEW YORK — A silo explosion killing a New York assistant chief was due to unrecognized hazards and the decision to close hatches at the top of the silo, according to a new firefighter fatality investigation.
Sackets Harbor Assistant Fire Chief Garrett W. Loomis was killed while responding to the fire on April 11 last year, according to the NIOSH report.
The 26-year-old volunteer firefighter had arrived on scene to notice open hatches resembling doors on the silo, and climbed up an attached ladder to close the hatches.
As he was descending, the silo exploded and caused part of the ladder to detach from the silo, sending Chief Loomis on a 30-foot fall to the ground.
A firefighter on scene performed CPR and Chief Loomis was transported to a local hospital where he died.
As a result of the death, NIOSH investigators are calling for fire departments to prepare and train on SOGs specific to firefighting at structures including oxygen-limiting silos.
According to the report, important elements that should be included in such SOGs for oxygen-limiting silo fire operations include:
- Confirm pre-plan information on arrival
- Do not direct water or foam onto the fire through the top hatches. This will allow oxygen to enter the silo and can cause a "backdraft-like" explosion of fire gases
- Do not enter, breach, or open any external silo hatches in an attempt to extinguish the fire
- If the top hatches are open, firefighters should not close them if there is smoke coming out from the top, especially if the silo is vibrating or making unusual sounds
- Lockout and tagout the electrical service to the silo
- Roof hatches should be safe to close if the silo has been quiet for several days and there has been no smoke coming from the hatches. The hatch should be closed, but not securely, to permit the relief of any pressure that may build up
- Leave the silo closed for up to three weeks or until the fire consumes all the oxygen in the silo and self-extinguishes
- Establish a collapse zone around the silo at least 1 and ½ times the height of the silo, keep unauthorized personnel away from the area, inspect for extension and protect adjacent exposures
- Ensure that all responders wear the appropriate personal protective clothing and equipment
- Some silos have external valves to inject carbon dioxide or liquid nitrogen from compressed gas cylinders to extinguish the fire
- If the silo still continues to burn, seek assistance from the silo manufacturer
Different silos, different dangers
Firefighters need to know the characteristics of different types of silos in order to respond effectively and safely, the report said.
Fires in conventional silos are slow burning and normally do not represent an explosion hazard, according to investigators.
The best method of attack is to use adjustable penetrating nozzles from the silo's access chute, rather than attempting to use carbon dioxide or nitrogen.
"It may be impossible to completely extinguish a fire in a conventional silo," the report said.
"The farmer may have to partially or completely empty the silo, with the fire department present to immediately extinguish any hot spots that flare up when oxygen reaches the smoldering fire."
For oxygen-limiting silo fires, the greatest hazard is the risk of an explosion.
Constructed from steel or concrete and bearing tightly sealed openings and hatches, a sealed silo of this type should not bear enough oxygen inside to support a fire.
Attempting the fight a fire in such a silo could actually prove catastrophic, the report said.
"Any attempt to extinguish a fire in an oxygen limiting silo may introduce oxygen into the silo, increasing the risk for a back-draft or explosion."
"Smoke emitting from the top hatches of an oxygen-limiting silo dictates that the top hatches should not be closed and secured."
Firefighters should "stay off" an oxygen-limiting silo if it is shaking, hot, noisy, smoking heavily or has been opened within the past few days.
In any situation, firefighters should seek assistance from the silo manufacturer or field representative, the report said.
In the incident killing Chief Loomis, crews did not recognize that the oxygen-limiting silo had already been breached by a previous fire nearby, which opened it for the prior three days.
As a result of the line-of-duty-death, NIOSH also recommends fire departments:
- Ensure that pre-emergency planning is completed for all types of silos located within fire department jurisdictions
- Consider requiring that placards with hazard warnings and appropriate firefighting guidelines be placed on silos
- Consider silos as confined spaces and recognize the dangers associated with confined spaces when responding to silo fires
- Ensure that an Incident Safety Officer is deployed at technical or complex operations.