Lisbon firefighters battle a fire Sunday night at 21 Mill St. in Lisbon where occupants safely escaped the home. The cause is being investigated. Lisbon Fire Department Facebook photo

LISBON — State officials are investigating a fire Sunday night that heavily damaged a home at 21 Mill St.

The occupants safely escaped, but it is believed two pets perished in the blaze, the Lisbon Fire Department posted on social media.

A state police trooper reported the fire at about 6 p.m., and by the time firefighters arrived, flames had engulfed most of the first floor, according to officials.

Lisbon Deputy Fire Chief Ryan Guay was first on scene and immediately struck a second alarm to bring mutual aid in from Lewiston, Durham, Topsham, Sabattus and Bowdoinham fire departments. Crews cleared the scene shortly after 11 p.m.

The Maine Office of State Fire Marshal is investigating the cause of the blaze, according to the Facebook post.

Lisbon firefighter Max Storm carries hose Sunday night to a burning house at 21 Mill St. in Lisbon. Occupants safely escaped the home, but two pets are believed to have perished. Lisbon Fire Department Facebook photo

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