The Ontario Fire Marshal is investigating after two homes were gutted by a fire over the weekend.

Vaughan firefighters were called to an 8,000 sq. ft. home at 126 Thornbridge Dr., in the area of Yonge and Centre Streets, at approximately 6:30 p.m.

The three-alarm blaze started in a house under construction and soon spread to the home next door. No one was home at the time.

"There's no way to explain. You lose everything you worked for for 30 years," Guido Rapone told CTV Toronto's Janice Golding.

Rapone owned the house next to the one that caught fire, and watched as the flames spread to his own house, where he's lived since 1987.

"You think of all the things in there: Thoughts, belongings, memories. And you sit there, helpless. You can't do anything."

York Regional Police evacuated other homes in the area as a safety precaution. Officials at the scene told reporters the heat from the fire was so strong that it melted some of the siding of a home across the street.

Officials have not said what caused the fire, which knocked out power to 84 homes in the area.

Crews were still on scene knocking out hot spots on Monday morning.