KALISPELL, Mont. -

Nearly a month after explosions and fire at the Plum Creek Plant in Columbia Falls, operations are returning to normal. The fire knocked down two production lines, one of which is back up and running. The other will be brought online soon.

"Line one is the thicker board line, that's the older line that was built in 1974, and we're continuing to repair that line and would expect in the next day or two we'll begin testing and hopefully, by Friday, be at full production," said Tom Ray, Vice President for Northwest Resources and Manufacturing.

Investigators blame the fire on a bearing in a conveyor belt. It failed and sparks from that caused a fire and explosion in air vents. Now, crews aren't just getting the machines back online, they are also working to make the plant safer.

"We put in heat sensors, we put in remote cameras and we've improved our fire system to make sure we have a safe environment for our employees and so we don't have a repeat in the future," said Ray.

After the fire, plant officials told us no jobs would be lost. That promise has been kept.

"We went from fire watch, to cleanup, to repair, now back to normal production. So everyone's continued to work on schedule and been a great success," said Ray.

If testing in the next few days goes well, the entire plant should be fully operational by Friday.