ST. CLOUD - We have an update for you on yesterday evening's fire at Northern Metal that filled east St. Cloud with black smoke and backed up traffic for blocks.

Fire officials now believe the blaze was intentionally set.

St. Cloud Fire Marshall Mike Post says the fire was first reported at 6:08 p.m., 40 minutes after the last employee left Northern Metal for the day.

Soon after, multiple eyewitnesses spotted charred flakes falling from the sky and popping noises.

No injuries were reported, but traffic was blocked for several hours along East St. Germain Street between Wilson Avenue and Lincoln Avenue, as well as along Lincoln Avenue from Highway 23 to several blocks north beyond the fire site.

While officials are certain the fire originated from a stack of 12 cars - three high and four wide - at this time, they aren't sure exactly what sparked the blaze.

Post says they are offering a reward of up to $2,500 to anyone who can help solve this crime. You're asked to call the arson hotline at 1-800-723-2020 if you know anything.