City Officials, Mayor: Gas Leak Caused E. Harlem Explosion

New York City Mayor Bill de Blasio said that a gas leak caused the large explosion in East Harlem Wednesday morning where two buildings once stood at 1644 and 1646 Park Avenue.

About 250 firefighters from 44 units responded to the explosion that destroyed the buildings, killing at least three people and wounding at least two dozen more, the New York Times reports.

Heavy equipment was used to clear destroyed vehicles outside the buildings as firefighters started the painstaking task of searching the rubble brick by brick. By late afternoon, they could be seen sifting through the wreckage, passing buckets of debris hand-to-hand to clear it from the site, reported the Paper.

By night time, rescue workers were still on site, continuing to search the rubble, hoping to find the nine occupants of the buildings still missing.

There was little warning-- certainly not enough to have safely evacuated the area, de Blasio said at a news conference: "This is a tragedy of the worst kind because there was no indication in time to save people," he said, warning the search "will take quite a bit of time."