Investigators are still trying to determine the cause of Thursday's building explosion in the East Village, and officials are looking into whether a gas line below now-crumbled restaurant Sushi Park at 121 Second Avenue was rigged to steal gas.

Mayor de Blasio floated the theory at a press conference yesterday, noting that it was possible "that the gas line was inappropriately accessed internally by people in the building." That theory hasn't been confirmed, but Sushi Park owner Hyeonil Kim told the Times that the gas line at 121 Second Avenue solely supplied his restaurant, and did not provide gas to the apartments above. "I don’t believe that there was no gas at 121 during this winter season,” he told the paper. “Somehow they got the gas, but how?"

NBC 4 reports that inspectors issued the building a safety violation after discovering a potentially rigged gas line in the building's basement over the summer, and investigators are looking into whether that was the case this time as well.

A general contractor, Dilber Kukic, had been working on the building, though according to officials, he did not have the proper permits for extensive gas work. Kukic was on the scene for the initial blast after the building owner's son reported a gas odor. Kim also smelled gas shortly before the blast, though he called his landlord instead of calling 911 or Con Edison. Con Ed workers had been at the building just hours before the explosion to inspect private plumbing work, but did not detect any gas leaks.

If you’re interested in donating money to help those affected by the East Village explosion, the Mayor’s Fund to Advance New York City is accepting donations. Checks should be made out to the NYC Mayor's Fund with a note that they are earmarked for the East Village Collapse. In kind donations are not being accepted at this time.