As officials continue their investigation of the propane gas explosion that obliterated all but a chimney of a house on Sunny Valley Road, the Greater New Milford community is reaching out to the victimized families.

One man was killed in the explosion Wednesday evening while trying to help the homeowner connect a propane heater.

Anthony Fratino III, 47, of New Milford died as a result of the accident and his 9-year-old son, Nicholas, was injured, as was 46-year-old John Wilkinson, who lives in the house with his wife, Alice.

Alice Wilkinson and the couple's two children were not in the house when it blew up, neighbors said.

Neighbors said Thursday morning Mr. Wilkinson had asked Mr. Fratino for help in connecting a propane space heater.

He had sent his wife and children out of the house when he smelled propane, neighbors said.

Mr. Fratino had run a New Milford-based plumbing and heating business.

Police spokesman Lt. Larry Ash said Mr. Wilkinson and Nicholas Fratino were hospitalized with severe lacerations and burns. Both victims were taken hospitals outside the Greater New Milford area.

Mr. Wilkinson is being treated in the burn unit at Bridgeport Hospital, while the 9-year-old victim was taken to a children's hospital in Boston.

The explosion happened at about 6:40 p.m., near the intersection with Sunny Valley Lane, across from the Sunny Valley Nature Preserve.

Bits of rubble were scattered over a wide area where the two-story, Cape-style farmhouse had stood, testimony to the violence of the blast. Only the chimney remained standing.

"It's just an incredible site; there's nothing left of the house," Lt. Ash said. "I've never seen anything like this."

Two ambulances left the scene afterward with lights flashing and sirens sounding, and police and emergency vehicles lined streets in the area.

Police ordered onlookers away from the scene, because of fears that asbestos particles from the house might be in the air, Lt. Ash said.

Some New Milford residents said the explosion was heard miles away.

Eric Bailey, who lives near the ruined house, said his family was sitting down to dinner when they felt the impact of the blast.

"I thought a plane or car ran into our house," Mr. Bailey said. "The entire house just -- boom! -- shook."

After the blast, police and fire crews initially searched for a possible fourth victim in the rubble. Police later said they determined no one else was at the house at the time it was leveled.

Still, Lt. Ash said, police planned to use a "cadaver dog" to make sure there were no human remains at the site.