SEDGWICK — A fire Saturday afternoon destroyed a large rental storage unit building on Route 172 and all of the contents inside, according to fire officials.

Eddie Naumann, who runs a separate auto repair business on the same property, said the large building had 150 storage rental units but not all of them had items stored in them. He said about a dozen cars were in storage in part of the building when the fire started around 3 p.m.

Approximately 50 to 60 firefighters from about a dozen neighboring towns responded to the blaze, according David Carter, chief of the Sedgwick Volunteer Fire Department. He said no one was hurt in the blaze and that the cause of the fire has not yet been determined. The State Fire Marshal’s Office has been notified, he added.

Naumann, whose Antique Auto repair business is in a neighboring building on the same property, speculated that a car he was getting out of storage in the now-destroyed building may have sparked as he and others were trying to start the car’s engine.

No one saw any spark and, after the engine wouldn’t start, they quit trying and walked away, Naumann said. A few minutes later, someone saw flames spreading in the storage unit where the back of the car was, he said.

Naumann said he and others tried to extinguish the flames with fire extinguishers and a garden hose, but to no avail.

Bill Brown, the owner of Sedgwick Storage, and his family consider every year whether they should continue storing motor vehicles at the site, because of the insurance costs it entails, according to Naumann. Because cars contain flammable fluids, he said, the insurance premiums for storing them are higher than for storing simple household items such as furniture and electric appliances.

Foster Blake, who lives just down the road, said he built the storage facility in the 1980s for use as a lumber yard. He said the part of the building nearest the road was about 140 feet long and 80 feet wide. He sold the property to its current owners in 1996, he added.

“It’s pretty sad,” Blake said. “There were some explosions” from cars catching fire.

The destroyed building once had been two separate buildings but they were connected at some point not too long ago with an addition, neighbors and fire officials said. The portion of the building where cars were stored, which is where the fire appeared to have started, is away from the road, while the section used for storing household items is next to Route 172, they said.

According to Carter, it took firefighters about 90 minutes to get the flames knocked down and under control. He said the business has insurance and guessed that damage from the fire would cost hundreds of thousands of dollars, if not more.

Carter said he has called for excavators to be brought to the fire scene to pull apart the burning pile of rubble so firefighters can make sure the flames are fully extinguished. The fire chief predicted that firefighters would have to remain at the site for some time in order to make sure flames did not rekindle in earnest.

“We’re going to have to be here all night, probably,” Carter said.