Update, Monday, June 18
Deputy Fire Marshal Alex Rauso has attributed the cause of the fire to an attic fan.
He estimated the damages to the home at $325,000 to $375,000, including structure and contents. He added that repairs could take at least six months.
The lone resident, Clare Coe, is staying with family, Rauso said. She bought the house with her husband, who recently died, according to numerous reports.
Update, 8:45 p.m.
The fire marshal's office has isolated the origin of the fire but the cause is still under investigation.
"The area of origin was definitely near the dropdown attic stairs," said Deputy Fire Marshal Alex Rauso.
"The main body of the fire was knocked down in 20 minutes," he added.
What one neighbor described as a fast-moving fire left a smoking, gaping hole in the roof of 49 Gatehouse Road Friday afternoon and caused serious interior damage.
"First my sister saw smoke. Then we started smelling it," said Gene Cellini, who called 911 about 4:45 p.m.
Then they saw smoke coming from gutters. "In two to three minutes all four corners of the house were smoking."
The smoke quickly turned from gray to black, then flames came from the roof peak. "It seemed like the entire top floor of the attic was engulfed in flames," Cellini said.
The owners are listed as Clare and David Coe, who bought the home in 1970, according to town property records listed online.
All three town fire departments, Nichols, Long Hill and Trumbull Center, responded. Nichols Deputy Chief Ray Franko said there was extensive damage to the second floor of the 2.5-story woodframe home.
The town fire marshal's office is investigating the cause.
"All companies did a great job," Franko said.
First Selectman Tim Herbst conferred with Fire Marshal Megan Murphy and the lone female occupant.
"Thank God she wasn't in the house," Herbst said. "She's doing remarkably well. Thank God, she's not injured."
He praised the fire departments for their "quick response."
"They are to be commended. It was a team effort," Herbst said.
The house is too damaged to be occupied right now.