The Duluth Fire Department responded to the report of a fire in downtown Duluth at 9:31 a.m. Saturday.
The fire marshal's office deemed the building, located at 118 East 1st St., a total loss.
The estimated damage from the fire is $1 million, according to the assistance chief's office.
As of 3:30 p.m. Saturday, crews had not yet entered the building due to the collapsing roof, said city of Duluth public information officer Kate Van Daele.
No people are believed to have been in the building at the time of the fire. However, the fire department still cannot yet confirm that, Van Daele said. Crews were able to check the basement level of the building and confirmed no people were present.
"We don't know how the fire started. We believe it started on the third floor of the building, which on the street level looks like the second floor, on the far eastern corner," Van Daele said Saturday morning.
The building owner told the fire department the space had been used as warehouse space in the last few years. According to the St. Louis County land explorer, the building is owned by Kevin Ruhnke.
The building shares a firewall with the adjacent Wabasha Bookstore. While no fire was reported in that building, the fire department has not yet confirmed if there is any damage to that adjacent building.
As of late Saturday afternoon, First Street was still blocked off between First Avenue East and Second Avenue East. Both avenues were closed off as well in the area of First Street. One crew remained on the scene to monitor the building and put out any hot spots.
Because the cause of fire is still under investigation, the fire department is asking for the public's help in providing any tips or information. Anyone who was in the area around the time the fire began should call 218-730-4380.
This story was updated several times with new information from the fire department. It was last updated at at 4:45 p.m. Nov. 21. It was originally posted at 11:42 p.m. Nov. 21.