Why are fruit warehouses destroyed by fire?

March 05-- Mar. 5--PESHASTIN -- A fruit warehouse caught fire Sunday, causing millions in damages and destroying tons of produce.

That sentence should sound familiar -- this is at least the sixth fruit warehouse in North Central Washington to suffer a major fire in the last four years, according to a Wenatchee World analysis.

The fire on Sunday destroyed a Blue Bird storage facility. Pine Canyon Growers' warehouse in Orondo caught fire in November, Phillippi Fruit lost one in 2017 and Blue Bird lost another warehouse in Wenatchee in 2015.

Some were caused by stray wildfire embers, one was from a faulty fan motor and another was brought down by burned apple syrup.

These fruit warehouses are particularly susceptible to fire because they're often older structures made from combustible materials, according to local fire marshals. And once a fire begins, it's often difficult and dangerous for fire crews to enter.

"If we can keep the fire out of them, then they're pretty safe. Once it gets inside, they can't really go into those buildings and put them out," said Chelan County Fire Marshal Bob Plumb.

A building's age is a big fire-risk indicator, said Douglas County Fire Marshal Kurt Blanchard.

"The older age class are obviously at higher risk," he said. "I think modern warehouses, built under current code standards, adequately meet the laws for fire protection."

But the older buildings may still have sawdust insulation or combustible asphalt roofs, he said. There are some that don't have sprinkler systems in their cold storage rooms.

"In our state, cold storage units are exempt from having to sprinkler," he said. "They don't have to and it makes a certain amount of sense because fruit in itself does not constitute a combustible commodity. It's not going to burn."

The real issue, Blanchard said, is the bins holding that fruit.

"The bins themselves also combust. One of the things I've found is a lot of warehouses are going from wooden bins to a plasticized bin," he said. "Those are certainly more ignition-resistant but the issue that we always find is once they catch on fire, the amount of thermal output they give out is very similar to combusted gasoline."

Wooden hallways are also a common problem spot, Plumb said.

"The (cold storage) rooms are sealed and there's an inert gas in there to keep fruit from spoiling so the fire hazard is pretty low," he said. "But in these older ones there's a mezzanine that runs down the middle, which has a wood-frame construction. If the fire gets into that, it'll run the length of the building and then get into the roof."

That can quickly create a dangerous situation for firefighters, so crews normally won't enter the building unless someone is suspected to be inside, Blanchard said.

"When these fires get really large, unless there's a life-safety issue, these firefighters are going to go into defensive mode," he said. "They're going to, as we term it, 'surround and drown.'"

Firefighters themselves also come into play, Blanchard said. These large agricultural buildings are often constructed in rural areas, which may have a smaller volunteer staff.

"They're limited in number and size and capability -- and sometimes even training because they're pulling people off the streets and training these guys," he said.

That forces many fire districts to call for backup resources when a big commercial fire ignites, he said.

"They'll often tone out to second alarm and third alarm," he said. "It's long distances and sometimes it's going to take over an hour to get resources there. So the timed response is an issue too."

The final element to consider is water. Rural areas don't often have ready access to sufficient water flow to feed a sprinkler system or a firefighter's hose, Blanchard said.

"The cost of bringing water out to these rural areas is always a challenge, both for the fire marshal who is applying the code and the developers and the investors," he said.

Some older warehouses used to tap into irrigation or a private well. But those sources can be problematic, Blanchard said.

A rural well might pump 15 to 20 gallons per minute but a warehouse sprinkler system might demand 1,500 gallons per minute, Blanchard said.

It comes down to a compromise between investment and resources, Blanchard said.

"We're always challenged with finding a balance between providing for public safety and, in a realistic manner, making it cost-effective for the investor without compromising that safety," he said. "So we're challenged to say the least."

Reach Reilly Kneedler at 509-661-5213 or (javascript required to see email). Follow Reilly on Twitter at @reillykneedler.

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