UPDATE | Dozens missing in NYC buildings collapse

NEW YORK (AP) — A thunderous explosion flattened two East Harlem apartment buildings today as utility workers were on their way to investigate a report of a gas leak, killing at least two people, injuring more than 20 and leaving over a dozen others unaccounted for.

The fiery blast rocked the neighborhood about 9:30 a.m., shattering windows a block away, hurling debris onto elevated commuter railroad tracks close by, and sending a plume of smoke over the skyline.

People went running into the streets, and the two five-story buildings on Park Avenue at 116th Street, near the northeastern corner of Central Park, were reduced to a burning heap of bricks and metal.

"It felt like an earthquake had rattled my whole building," said Waldemar Infante, a porter who was working in a basement nearby. "There were glass shards everywhere on the ground, and all the stores had their windows blown out."

Con Edison spokesman Bob McGee said a resident from a building next to the two that were destroyed had reported smelling gas inside his apartment and thought the odor could be coming from outside.

The utility dispatched two crews just after 9:15 a.m., but they arrived just after the explosion, McGee said.

Police said two women believed to be in their 40s were killed, and two of those hurt had life-threatening injuries.

Fire officials said more than a dozen people were unaccounted for. Mayor Bill de Blasio said some may have made it to safety.

Four hours after the blast, firefighters were still dousing the flames with water, and rescue workers had yet to venture into the debris to search for victims.