A small explosion is the likely cause of damage to a Motel 6 in West Duluth Friday morning.

At about 9:15 a.m., the Duluth Fire Department responded to a report of smoke coming from the walls of the Motel 6 at 200 27th Ave. W., prompting an evacuation of the building.

In short order, firefighters had hoses attached to hydrants and were entering the building wearing oxygen masks.

Firefighters found heavy smoke in a hallway and multiple rooms, including a utility room, a news release said. It was determined that a small explosion caused damage to the utility room ceiling and broke a window.

Firefighters quickly extinguished all visible flames and removed interior and exterior wall coverings to find more flames in several locations to extinguish, the release said.

The whole building shook

Ralph Czuczko, a guest staying on the second floor of the motel, said: "I was watching TV when I heard a boom, and I felt the whole building shake. I thought maybe a truck had run into the motel."

Thomas Bainbridge, a guest staying on the first floor with his wife, Laura, said he, too, heard the noise and felt the reverberations.

"I grew up in Manchester during 'the troubles,' so when I heard a boom, I knew what to do: You get out of there quick," he said.

Fabiola Droguett, another guest, said she had been doing a load of laundry and noticed a smell like natural gas in the hall, where she also saw what looked like steam.

Alarms sounded in the building, as guests headed for the exits.

Czuckso and Bainbridge said they both observed gray smoke in the hall and when they got outside, they saw an electrical transformer sparking heavily.

Firefighters remained on scene for two hours and the fire is still under investigation by the Duluth Fire Marshal’s office. There were no injuries and initial damage estimates to the building totaled $100,000.