Firefighters from 22 different departments were called to a two-block-long warehouse fire in Green Isle that started early Wednesday morning and taxed the water supply in this city of 450 residents, forcing the other fire departments to bring tanker trucks and aerial tankers.

Several LP gas tanks stored inside the structure exploded as firefighters battled the blaze for several hours, said Green Isle Fire Chief Dean Stoeckman.

“We couldn’t fight it from the interior,” Stoeckman said. “We had to pour water on it from outside.”

Authorities said a cutting torch likely sparked the fire, where three people were working, at the 98,000-square-foot warehouse. All escaped without injury.

Sibley County Chief Deputy Pat Nienaber said the blaze at Shamrock Storage was reported around 10 a.m. as workers inside the warehouse were cutting metal with a torch.

Firefighters arriving on the scene found the warehouse filled with smoke and intense heat.

Workers in the adjacent OEM Services building were evacuated.

The warehouse contained stored PlayStations and Nintendo video games, Stoeckman said. Firefighters were to remain on the scene overnight, continuing to demolish the building to find remaining hotspots. About 10 firefighters were keeping watch on the structure overnight, Stoeckman said.

City Clerk and Treasurer Paula Geisler said the building is called Shamrock Storage and covers two city blocks on the north side of town.

She said the building stored semitrailer trucks and other items. Whatever is burning inside, she said, every so often “keeps going boom.”

Some nearby homes have been evacuated, and the elementary school was being used as an evacuation center for those who needed to get away from the smoke.

The official cause of the fire wasn’t determined. Officials did not release further details.

Green Isle is about 37 miles north of Mankato.

The Associated Press contributed to this report.