The blast happened around 1:37 a.m. in Elmont.
The home in which the explosion occurred collapsed, while the neighboring houses also caught fire. It took a massive response from firefighters to knock down the flames.
Residents living in the homes on either side were able to escape without injury.
A number of residents in the neighborhood had to be evacuated.
A friend of the homeowner says he is in the hospital preparing for gallbladder surgery and has been out of the house for a week. He got word this morning that his home was gone.
"He's a bundle of nerves, he was basically crying," Brian O'Neil said. "I was just trying to help him out. I came back here to see what the result was. I was trying to take pictures, and it's just a very sad situation. He's in shock. I'm in awe right now."
Three firefighters were treated for minor injuries.
The incident is under investigation by the Nassau County Fire Marshal's office, as well as the arson/bomb squad from the Nassau County Police Department.
Police say guns and ammunition were found inside the home. The home owner is apparently an avid hunter.
The fact that the weapons and ammunition were found inside the home is making it difficult for investigators to get inside to see exactly what caused the explosion.
No one reported the smell of gas before the blast.