Authorities are unsure what caused the fire that consumed a Second Street home Friday night in Baraboo.

The blaze left about 70 percent of the home scorched, and took the life of a Labrador Retriever, said Baraboo Deputy Fire Chief Steve Pointon.

Baraboo Police Department officers reported the blaze at the home of Angela Kolar to the fire department a little after 9 p.m., Pointon said.

It started in the kitchen at the rear of the house, he said, and progressed to the second-floor attic area. But Pointon said a follow-up investigation this weekend did not offer any clues as to what started the fire.

The owners were not home when it started, Pointon said, and one of two dogs was able to escape through a small pet door.

Because of the weather and the intensity of the flame, the North Freedom and Delton Fire Departments were called in to assist.

"They get pretty whipped in that heat and humidity," Pointon said. "That's when you need the extra help."

Baraboo District Ambulance Service also responded, but there were no injuries, Pointon said.