SIOUX CITY, Iowa (KCAU) — UPDATE: Sioux City Fire Rescue (SCFR) provided new information on the early morning structure fire.

According to a release, SCFR responded to a structure fire at the 1500 block of Steuben St around 2 a.m. on Monday.

The release stated that firefighters reported heavy smoke visible from the one-story commercial building upon arrival.

Upon entering the structure, firefighters encountered heavy fire throughout the building. Due to high heat and weakening of the structure, firefighters exited the structure and water was applied from the outside.

The release indicated that several propane tanks that were used for forklifts inside the structure had ruptured causing explosions that further weakened the structure.

The building was used as a freight transfer facility, consisting of approximately 62 overhead doors. There were no people inside the structure at the time of the fire, according to the release.

The structure sustained heavy fire damage throughout and has been red-tagged by City Inspection Services. Several tractor-trailers parked near the structure also received varying amounts of damage.

SCFR stated the cause of the fire is still under investigation and will be released when completed.

— — —

PREVIOUS: Several fire trucks were called to the scene of a fire at a Siouxland business on Monday morning.

Sioux City Fire Rescue was called to Chicago Central & Pacific Railroad on Steuben Street around 2 a.m. where there was a substantial structure fire.

Officials said around 4 a.m. that they were still working to get the fire under control, and at least five trucks could be seen working to put it out.

The investigation is ongoing and the cause of the fire is unknown at this time.

This is a developing story.