Fire in northwestern Wisconsin destroyed a building used by an animal rescue group and killed two of the sanctuary's Great Danes, the facility's operators said.

The Great Dane Rescue of Minnesota and Wisconsin, southwest of Siren, also lost all of its supplies in Thursday morning's fire.

The sanctuary, roughly 17 miles from the Minnesota border, serves the Midwest for in-home placement of Great Danes as well as a permanent place for dogs that cannot be adopted for various reasons.

Rescue staff reported the fire in the 8200 block of Waldora Road about 7 a.m. The blaze was extinguished, and the circumstances about the fire remain under investigation. No people were inside at the time.

Feeding bowls, food, blankets and other donated items were lost in the fire.

"It's hard to grasp how much of a loss this is for all of us involved with the rescue. I can't explain how painful it is to know that two of our beloved boys are gone," said kennel manager Jasmine Jones. "We lost everything we use to provide the rescue services we offer — our building and all of our supplies."

Donny and Whinnie were the two male dogs lost in the blaze, Jones said, adding: "We lost two giant hearts."

A second building on the rural property was saved by firefighters and continues to house about a dozen Great Danes, said Arianne Bartels, who along with husband Adam provides foster home services for the facility.

Anyone wishing to help the nonprofit group recover from the fire can donate via the group's Facebook page or PayPal: gdromn@gmail.com