An abandoned sugar mill on Sunday caught fire, sending thick, black smoke into the air in Longmont.

It happened just after 6:30 p.m. off Sugar Mill Road. When firefighters arrived, they found the smoke coming from the south side of the main building.

Crews from Longmont and Mountain View Fire Rescue will be working on finding hot spots Sunday night.

No injuries were reported.

At this time, no cause has been determined.