The Jan. 18 fire that caused extensive damage to Riverside Bake Shop and Reeses Barkery and Pawtique in downtown McHenry was accidental, a McHenry County Fire Protection District fire investigator has determined.

The Sunday morning fire at 1309-1313 Riverside Drive was caused by heat from a torch used for re-roofing work done that morning, an investigation determined. The torching raised the temperature of old, dry wood boards underneath the roofing materials “until they reached their ignition point,” according to the report.

The fire investigation report was completed on Jan. 29. The blaze caused an estimated at $1 million in damage to the building and $500,000 in losses to its contents, according to the report authored by investigator Brent Innes.

After repairs are made to the building, Carol and Bernie Rice, owners of Riverside Bake Shop, a longtime downtown business, indicated in a GoFundMe update that they are looking to reopen late this year.

“Clean up is moving forward with an optimistic opening date in November,” a post on the site, signed by “Carol and Bernie,” reads. “Updates will be provided and once again we cannot thank you all enough!!!”

Tenant and pet product provider Reeses Barkery has moved around the corner to 3314 Pearl St. for the time being.

The Rices had contracted with Chicago-based APR Roofing to install a rolled-rubber roof on the Riverside Drive building, according to fire district investigation report. The roof work was done at the request of their insurance company, which had cited minor leaks, according to the report. The roofing company had the proper permits from McHenry, and is in good standing with the Illinois Secretary of State, according to the report.

The moderate wind speeds that morning, and cold temperatures, helped to prolong the initial heating to the underlying wood, Innes wrote. “The fire then spread ... into the exterior of the roof line and the void space beneath,” according to the report, adding the fire had likely been burning for an hour before it was noticed.

The south side of the building’s roof partially collapsed during the blaze, and most of the fire damage was concentrated in the plaster and lath ceiling and the roof.

A passerby came into the bakery and warned those inside that the roof was on fire, according to the report, which added that investigators were unable to locate or identify who that passerby was.

According to the report, three roofing workers were interviewed by inspectors while firefighters were still working to put out the fire. The men told investigators they’d worked until 11:30 a.m., turned off their propane torches, watched for a few minutes to ensure there were no issues and then went to their truck to eat lunch.

They found the roof on fire once they returned and attempted to put it out using fire extinguishers, according to the report.

No one from APR Roofing could be reached for comment Wednesday.

The fire was reported to 911 at 12:07 p.m. Firefighters and investigators remained on the scene until after 5 p.m. There were two injuries, one to a person who fell or jumped, and one to a firefighter hit by debris. Both were taken to Northwestern Medicine McHenry Hospital for injuries not considered life-threatening.