Transcript for 7-Alarm Fire, a Building Collapse in New York City's East Village
Now, to that breaking story right here in New York City tonight. A seven-alarm fire. Reports of a massive explosion. A five-story building engulfed in flames. The skyline filled with smoke. There were reports late today of people trapped, then jumping to safety. And now, the fears tonight, was this a gas leak? ABC's Ron Claiborne on the scene. Reporter: Witnesses say a thunderous explosion rocked the five-story building, then, within seconds, fire engulfed it. I heard a huge explosion. A massive explosion and I could see the structure fall. Reporter: He says the front fire escape, still intact in this photo he took seconds after the explosion, collapsed, forcing people trapped inside to leap from the windows. Hundreds of firefighters poured in to battle the raging inferno. Dense black smoke making it almost impossible to see just a few feet. The cause still unknown, but suspicion immediately pointing at gas. Just last month, this explosion in New Jersey, caught on camera. And almost exactly one year ago, another gas explosion in new York City killed eight people in east Harlem. At this hour, firefighters still on the scene, you see them there in the thick smoke, pouring water into this smoldering remains of the building. But it will be awhile before they can get inside of that building and see if there's anyone in there injured or possibly dead. David? Ron Claiborne on the scene for us tonight here in New York.
This transcript has been automatically generated and may not be 100% accurate.