The Department of Environmental Protection said a nut linking a fuel injector and a pump may have led to a four-alarm fire at a Harlem wastewater treatment plant in July. The fire led to the dumping of millions of gallons of sewage into the Hudson River.
Officials released the findings of an investigation into the incident on Tuesday. They say the nut may have been under- or over-tightened, causing a small opening that may have allowed a hot spray of fuel to spark the fire.
But officials said the cause of the fire is likely to remain unknown, due to the heavy amount of equipment damage at the plant.
NYC Environmental Protection Commissioner Carter Strickland said in a statement that "While the initial cause could not be determined with absolute certainty, the report includes a number of steps that DEP can take in the future to minimize the risk from failures of such small pieces of hardware at North River and at similar DEP facilities throughout the city."