The basement fire was reported at a home on Hallock Place in Armonk around 11 p.m. The flames quickly spread through the entire house and could be seen shooting through the roof.
By 11:30, firefighters had abandoned their attack from inside and were fighting the fire only from the outside.
It is not known if anyone was in the house at the time.
Firefighters say the blaze was especially tough because getting water to the site was an issue early on.
A lightning strike is believed to be the cause.
Fire officials say the $3 million home belonged to a prominent investor.
WAKE UP WITH EYEWITNESS NEWS! Click here to download the WABC Eyewitness News Alarm Clock app from iTunes. or search WABC or 7online in the app store.
Get Eyewitness News Delivered