BOSTON (CBS) – A heater caused a three-alarm fire inside a brownstone near the Public Garden Wednesday morning, leaving $5 million in damage.

WBZ NewsRadio 1030′s Mark Katic reports

Firefighters were called to 17 Commonwealth Avenue just after 9 a.m. after flames were spotted in the duct work in the fourth floor ceiling.

Investigators said an in-floor radiant heater was mounted in that ceiling to heat a fifth floor room.

There are three condos in the brownstone.

Inside the brownstone after the fire. (Photo courtesy: Boston Fire)

Only one person was home at the time and he escaped safely.

Boston Fire Dept. spokesman Steve McDonald said the fourth and fifth floor are now gutted and there is heavy water damage on the third.

“I looked in the living room, beautiful living room with a nice chandelier and there was just water pouring out of the ceiling,” McDonald said.