ALDEN — A fire in rural Alden that destroyed a home a week ago started in the basement, according to officials.

The first and second floors of the house at 21751 620th Ave. collapsed into the basement, leaving behind extensive damage and debris.

“When the floors fall in like that, it’s a good indicator that it started in the basement,” said Doug Johnson, a member of the Freeborn County Fire Investigation Team.

Johnson said the initial investigation of the house indicates the fire began in the boiler room, though investigators have not been able to reach it yet.

“It’s very difficult for us to get inside that boiler room because of everything that collapsed and fell,” he said. “But with talking to the occupants and witness statements, everything is pointing to that boiler.”

The boiler used fuel oil. There was also a lot of combustible storage in the house, Johnson said. He said he thinks the fuel oil was somehow ignited and started the room on fire.

He classified the fire as accidental.

The house was owned by Bruce and Wendy Niebuhr, who were visiting their daughter about two miles away when they received a call about the fire.

They had lived in the house for 23 years.

Firefighters from Alden, Freeborn, Conger, Wells, Walters, Manchester, Minnesota Lake, Albert Lea Township and Kiester fire departments battled the blaze, and no one was injured.

The house was a total loss.

Johnson said the state fire marshal’s office and the Niebuhr’s insurance company reached the same conclusion as local investigators.

The fire was not suspicious in nature, and the home was locked and secured when firefighters arrived at the scene, he said.