A fire at a Burlington Northern Santa Fe taconite-loading facility in Superior kept firefighters busy for several hours Wednesday.

No one was injured, and no damage estimate was available late Wednesday.

The fire at the facility near 40th Avenue East and Itasca Street was called in at 5:18 a.m., the Superior Fire Department reported. Crews found flames and smoke showing from a 40-foot-long metal building and about 150 feet of a conveyer belt leading to the building.

BNSF safety personnel confirmed that all personnel were safe. The fire was extinguished in about 90 minutes, and crews remained on the scene until just before noon to extinguish remaining hot spots and conduct overhaul operations.

The cause of the fire had not been determined as of late Wednesday afternoon and remains under investigation. The shipping season is on winter hiatus, and BNSF spokeswoman Amy McBeth said the conveyer belt was not operating at the time of the fire.

McBeth said there was some damage, but information on the extent of that damage was not yet available.