Images from the scene: Scarsdale explosion: Click for a gallery of photographs
Authorities say the smell of gas led to the evacuation of workers on the scene just before the explosion.
Police said no one was injured in the afternoon blast.
Scarsdale Fire Department Chief Thomas Cain said construction workers with a backhoe had cut into or dislodged a gas service line and called the fire department when they smelled the gas. When he arrived, he ordered the workers away - just in time.
"As they were walking off the property and we were about to investigate, the house blew," Cain said. "We're very fortunate that nobody was hurt."
Neighbor Shelley Larsen, who lives across the street, said, "You heard the biggest boom that you could imagine, and then there were flames shooting out of the house."
Firefighters put out the blaze, and Consolidated Edison utility workers were able to cut off the gas to the house's line.
The house was reduced to blackened debris except for the front wall of a two-car garage, which was leaning sharply. Some debris flew into neighboring yards, but there was no apparent damage to other houses in the area of million-dollar-plus homes.
