Jankowski said he did not know when the 500-gallon propane tank buried in the backyard of 305 Webbs Hill Road would extinguish itself.
He said the exact cause of the explosion that leveled the 6,000-square-foot house had not yet been determined.
The investigation, being pursued by city Fire Marshal Charles Spaulding, Turn of River Fire Marshal Peter Bernstein and Deputy Fire Marshal Nicholas Jossem, along with state fire investigators, would likely take a few days more, Jankowski said.
According to officials with knowledge of the investigation, the homeowner, Giuseppe “Joe” Cardillo, 54, told police that just before the explosion he had mowed the lawn and sat down to have a sandwich.
He then went out into the backyard and lit a cigarette. Cardillo told investigators that as soon as he lit the cigarette, the house exploded, officials said
Wednesday. Cardillo, who at first did not want medical attention, was taken to Stamford Hospital and he was treated and released.
One official said Cardillo heated his house with oil, and that the propane was being used to heat a pool in the backyard and operate a backyard gas grill. Jankowski said about 280 gallons of propane had been put into the tank between one and two months ago.
Police and fire officials believe the explosion may have been caused by a buildup of propane fumes in the home’s basement that could have been set off by a spark from anything.
The fire and police departments’ joint arson team was called out Tuesday to help investigate the blaze, Jankowski said Wednesday at the Stamford courthouse, where he was testifying in a trial challenging the consolidation of the city’s five volunteer fire departments with the city’s professional fire department.
No evidence of arson had been found, Chief Jon Fonteau said Tuesday, but the property would continue to be treated as a crime scene until criminal wrongdoing can be ruled out.
Hours after the blaze on Tuesday, Fontneau described the property where the house once stood as “a scene from hell,” with debris from the house blown out as far as 400 feet away, and two nearby houses damaged.