Wood dust caused Plum Creek MDF explosion

But exact location not known yet

———

It will take some time to pinpoint the exact origin of an explosion and fire that heavily damaged Plum Creek’s medium density fiberboard plant on June 10, Columbia Falls fire chief Rick Hagen said.

The large explosions were caused by dust that mixed with air and ignited, blowing metal sheeting off exterior walls and heavily damaging the plant, Hagen said. No plant workers were injured.

The fire investigation is ongoing, Hagen said. Plum Creek personnel in the coming days will go over computer records for the fire suppression system to pinpoint the exact origin of the explosions and fire, he said.

The explosions drew a countywide firefighting effort, with nearly 70 emergency services personnel on the scene at one point. The initial call came out at 3:10 p.m., and firefighters were off the scene about 9:45 p.m.

Firefighters returned about 4 a.m. when a fire was found in a different building within the MDF plant. Crews returned from that smaller fire around 9 a.m.

The MDF plant uses powerful grinding machines to reduce wood into fibers that are treated with resin-based glue and squeezed at high pressure and temperature into panels. The fibers and sawdust can be very explosive when mixed with air, but the plant has an extensive fire suppression and detection system.

Hagen called this incident a “perfect storm,” where the fire resulting from the explosion outran the suppression system. Even so, the sprinklers played a significant role in partially suppressing the fire, which could have been much worse, he noted.

“The fact that no one was hurt was very good news and remarkable,” Hagen said.

Plum Creek maintains its own fire hydrants at the site, as well as a 3 million gallon water tank, Hagen said. The cool and rainy weather during the blaze also helped. The biggest problem for firefighters was accessing the fire in the sprawling facility. Plant workers helped guide firefighters where they could, Hagen said.

The last big fire at the MDF plant occurred in the early 1990s, when firefighters fought a big blaze in subzero weather.

Firefighters from across the valley attacked this week’s fire as three separate divisions under one incident command.

“Flathead County’s mutual aid system worked well,” Hagen said. “Every bit of resources we requested were delivered in a timely fashion.”

All told, 19 Columbia Falls volunteer firefighters fought the fire, along with firefighters and personnel from the Kalispell, Evergreen, Whitefish, Bad Rock, West Valley, Bigfork, Blankenship, Glacier Park International Airport and Marion fire departments, Flathead County Office of Emergency Services, Flathead County Sheriff’s Office, Columbia Falls Police Department and Three Rivers EMS.

The ALERT helicopter also responded, but no one was transported. Hagen said some firefighting resources in the valley were held back in case an emergency occurred elsewhere.

Just how badly damaged the MDF plant is and how long it will take to restart remains to be seen. While some panels on the building were damaged, structurally the building was sound.

A Plum Creek representative did not immediately return a call seeking comment.