South Old bridge fire department got the call at 11:15 for a gas leak in the residence on Grace Drive in Old Bridge.
Firefighters arrived two minutes later to find the house in flames.
Officials said a private contractor was working on the house and accidentally hit a gas line. The contractor then immediately evacuated the home.
Firefighters rescued an 80 year old woman, who was the only other person inside the house at the time.
About a minute later the house blew up, officials said. The house was blown off the foundation, knocking down the front, back and side walls.
Fortunately, no one was injured.
40 firefighters responded from five different towns.
Authorities said the home will be torn down tonight.
The homeowner and his family, who were not home at the time, will stay with friends and neighbors.