A fast-moving fire gutted Moozy's in Belmont, Massachusetts, early Thursday morning, sending heavy, thick smoke through the popular ice cream shop and collapsing the first floor. No one was hurt.

The fire appears to have started around 4:30 a.m. while the store on Trapelo Road was still closed. Chris Mahoney, an employee, said he was driving by to get coffee when he saw smoke pouring out of the building and called 911.

When firefighters opened the door, the smoke came billowing out. Mahoney said he did not want to open it himself and handed a firefighter the key instead. The fire chief said the flames started in the basement, then grew intense enough to bring down the first floor.

Several soft serve machines that could be seen through the window are now gone, part of the damage left behind after firefighters from several nearby towns came in to help. Belmont is about 10 miles west of Boston, and the scene drew a response from a community that knows the shop well.

Owner Dante Mussioli said the building was put up 10 to 11 years ago, and the loss hit hard because the store had become a place people returned to again and again. He said it was heartbreaking to see it happen and was grateful no one was inside.

Becca Pizzi, the manager, said Moozy's meant everything to the town and served generations of local families. She said people came in to celebrate happy beginnings there, making the fire feel especially painful. Mahoney said his daughter works there too, and that she was already home crying because this was her job.

There is still no word on what started the fire. For now, the central fact is that a beloved shop that had stood for more than a decade is badly damaged, and the cause remains unknown.