A fire that started shortly before 4 p.m. Thursday and quickly devoured several businesses and apartments in downtown Austin is believed to be one of the biggest ever to destroy multiple commercial buildings in the city, the city’s fire chief said.

There were no injuries reported during the fire, which occurred on one of the coldest days of the year with temperatures of 15 degrees below zero.

Austin Fire Chief Dan Wilson said that because neighboring fire departments were called early on to contain the fire, which started in a clothing store owned by a neighboring business, the Mi Tierra restaurant and grocery store, several other buildings are salvageable.

This is the second fire this year for Mi Tierra; the first occurred over the summer in the grocery store, and was contained before major damage was incurred.

The cause of the fire is still unknown, Wilson said. The state fire marshal, Steve Wolf of Stewartville, was called to investigate the fire, but cannot enter the area until possibly this morning, he said.

Firefighters from Albert Lea, Blooming Prairie, Brownsdale and Rose Creek battled the blaze, which ravaged the old, two-story structures and destroyed all of Mi Tierra’s businesses. Several others — Top Ten Nails, Marty’s R-C & Hobbycraft and Two Bears Trading Post — will likely sustain some fire damage.

“This was a very defensive fire early on,” Wilson said.

The chief said that residents and employees in the block were vacated immediately. When he first arrived on the scene, he was told one woman could possibly still be in an apartment above the clothing store; the woman was finally contacted via cell phone and confirmed not to be in the building.

Hansen Excavating of Austin arrived with an excavator to tear charred portions of the buildings down to vent the fire, which continued to grow and move through the roofs.

The fire chief said that a fire plan was in place for the buildings, and there was a sprinkler system in the Mi Tierra grocery store and restaurant; however the fire moved above the ceiling and sprinkler system, engulfing the roofs.

The clothing store — the source of the fire — did not have sprinklers.

Members of the American Red Cross brought in sandwiches, chili, coffee and water for the firefighters and law enforcement.

“We’re just trying to help them out,” said volunteer Joel Luker. “It’s no problem at all.”

Wilson said that after the fire is extinguished, the cleanup will be extensive and half of the block will be removed.

Residents watched the incident from street corners, while dozens of others took shelter inside local businesses to escape the blistering cold. Many took photos and video footage from their cell phones.

“I think this is something we always feared, a fire in the middle of a block like this,” said Sarah Douty, director of the Austin Main Street Project, which works to revitalize downtown businesses. “It puts all of the other buildings in danger. It’s not always something you can prevent, but it’s concerning.”

Roger Kahle, owner of the nearby Raymond James Financial Services Inc., watched the effort closely.

“I was a little nervous because my building is right across the street,” he said. “But there’s not much you can do about it, just stand here and watch it. And it’s the coldest day of the year. It’s kind of a helpless feeling.”

By 5:30 p.m., many downtown businesses were closed, but several, including the Tendermaid Sandwich Shop, Coffee House on Main and Anytime Fitness, were still open.

Les Traff, a longtime Austin resident, watched the fire from inside Bonnie’s Hallmark.

“It’s kind of a surprise,” he said. “It looks like they have good coverage. It’s been a real nice day up until this.”

Firefighters from Austin and surrounding areas were called to the scene, and law enforcement quickly closed off the portion of Main Street between Third and Fourth avenues northwest.

Temperatures at the start of the blaze hovered around 13 below zero.

Motorists were forced to work around the location and the town where traffic is almost non-existent quickly became rush hour.

Onlookers took pictures with cellphones and kept a close eye on the blaze.