KETCHUM, Idaho (AP) — Ketchum fire officials are investigating the cause of a blaze that damaged a house estimated to be worth $2.5 million.

The Idaho Mountain Express reports that construction workers involved in a remodel noticed the fire Monday. The blaze consumed the roof and the southern section of the house before spreading to the main portion of the home.

Ketchum Fire Chief Mike Elle says the flames became so intense that firefighters had to be removed from the house shortly after they arrived. In total, 57 firefighters were involved in battling the blaze.

The six-bedroom, seven-and-a-half-bathroom house is about 8,000 square feet and had a taxable value of $2.5 million in 2015. Including the value of the land, the entire property is estimated at $4.06 million.