One man was killed and two others were critically injured after an apparent propane explosion at a home in Connecticut Wednesday.

Police said the homeowner, John Wilkinson, 46, called his friend, Anthony Fratino, 47, to help fix a propane leak in the water heater in the basement of his home in New Milford, Conn.

The explosion happened around 6:40 p.m., according to reports.

Fratino was killed instantly, officials said. Wilkinson and Fratino's 9-year-old son, Nicholas, who was at the home at the time, were rushed to Danbury Hospital in Danbury Conn., with severe lacerations and burns.

Nicholas, police said, will soon be transported to a hospital in Boston, more than 150 miles away.

Wilkinson is being treated at the burn unit of Bridgeport Hospital, in Bridgeport, Conn.

Wilkinson's wife, Alice, and their two kids reportedly left the home shortly before the explosion and were at a neighbor's house. Police investigators said Wilkinson had told his family to leave the house when he smelled propane. It was not clear where the family is staying now.

Bits of rubble were scattered over a wide area where the two-story farmhouse had stood. All that is left of the Wilkinson family home now is the chimney, NBCConnecticut.com reported.

"It's just an incredible site; there's nothing left of the house," New Milford Police Department Spokesperson Lt. Lawrence Ash told The News-Times in Danbury. "I've never seen anything like this."

After the blast, police and fire crews searched the rubble for any remaining victims. While they determined no one else was at the house at the time it was leveled, Ash said police still plan to use a cadaver dog to make sure there were no human remains at the site.

Police ordered onlookers away from the scene because they feared asbestos particles from the house may be in the air, Ash said.

Some New Milford residents say they heard the explosion from miles away.

"It shook my entire house," another neighbor, Patricia Bailey told NBCConnecticut.com. "I had no idea what that was."

"I thought a plane or car ran into our house," Eric Bailey, who lives near the ruined house, told The News-Times. "The entire house just - boom, shook."

Officials advise anyone who smells a gas leak in their house, workplace, or around any gas equipment or appliance to leave the area immediately and call a trained propane service person and the fire department.

New Milford is in western Connecticut close to the New York state border.