The front yard of a Rock Island home at 3128 11th St. is littered with debris after an early morning explosion and fire May 15, 2007, which destroyed the home and heavily damaged two others. The explosion, at about 1:30 a.m., rattled windows more than a mile away.

Natural gas that built up in a vacant Rock Island house that exploded early Tuesday came from a faulty or worn flexible connector line to the kitchen stove and was ignited by the pilot light of the water heater, Rock Island City Fire Marshal Jeff Hindman said Wednesday.

The explosion and fire destroyed the house at 3128 11th St., and damaged D.B. Electronics store and another house to the north. Damage estimates to all three properties involved in the explosion were about $200,000, Mr. Hindman said.

Fire crews were called back to the house Wednesday afternoon to extinguish a hot spot smoldering in a remaining part of the building, Mr. Hindman said.

Once fire crews extinguished the hot spot, construction crews planned to demolish the house, which would allow the city to reopen the fourth lane of 11th Street, Mr. Hindman said. He expected the demolition to occur later Wednesday or Thursday.

Firefighters and crews from MidAmerican Energy Co. suspected a natural gas leak as the cause of the explosion from the start. After completing their investigation Wednesday, Mr. Hindman said they pinpointed the cause of the explosion to a faulty or worn flexible gas connector line to the stove in the kitchen. The gas built up in the house until it reached the pilot light of the water heater, he said.

Normally, gas leaking from small holes at the connector would cause an odor or strange smell and someone would report the problem before it gets to the explosion stage as occurred Tuesday, Mr. Hindman said. But because no one lived in the house, the problem went undetected, he said.

No one was injured in the explosion that blew the front door and window glass across 11th Street and into the driveway of the 11th Street Barber Shop. The explosion was heard several blocks away.