Duluth, MN – Officials have confirmed that an explosion fueled the fire that destroyed the office building at Lake Breeze Motel Resort on Wednesday.

“We know we had a propane explosion” — but what ignited the explosion is still under investigation, Duluth Fire Marshal Marnie Grondahl said.

Propane was used to fuel a water heater and furnace in the two-story building, which contained the resort’s office, gift shop, sauna and two motel units. Fire officials estimate the fire caused at least $350,000 in damage — $200,000 for the building and $150,000 for its contents.

Paula Hughes, the resort’s co-owner, remained in fair condition in Essentia Health-St. Mary’s Medical Center on Monday with burns.