PHILADELPHIA (AP) - Mayor Michael Nutter said Tuesday it would be "pure speculation" to say a contractor's cigarette caused a gas explosion that leveled a Philadelphia home, injuring eight people.
A deputy fire marshal told reporters that investigators have not been able to interview the injured worker, who is in critical condition with burns following Monday's explosion.
Furthermore, Nutter said, the city hasn't been able to confirm that gas was leaking at the time, correcting a city statement previously that a gas leak was to blame for leveling the unoccupied home, which was being remodeled.
Councilman Mark Squilla had said earlier at the scene that a contractor had been trying to light the pilot on a water heater. He said neighbors reported that the man lit a cigarette at one point and the house exploded.
"That is pure speculation at this point," Nutter said Tuesday at a news conference.
The mayor said all work at the site requiring permits were completed Friday, including installation of the hot water heater, and only cosmetic work was being done. He said the worker inside apparently was doing floor work for which no permit was required, but officials haven't yet been able to confirm that detail.
Nutter said more than 20 residents will be allowed to return to their homes Tuesday night.
The blast came less than two months after a collapse at a Philadelphia demolition site that killed six people.
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