By Caroline Moss, Pamela Engel and Harrison Jacob From Business Insider

Three people died and at least 64 others were injured in a massive building explosion in Harlem early Wednesday, ABC 7 reports.

Nine people are still missing, and rescue crews have been sent in to search for those who might be trapped.

Hundreds of police and fire officials responded to the explosion at an occupied building on 116th Street and Park Avenue in Manhattan. It happened at 9:13 a.m.

The cause of the explosion was a gas leak that had been reported to the power company ConEd 15 minutes earlier.

The explosion brought down two buildings at 1644-1646 Park Avenue. ConEd recieved calls about a heavy gas odor 15 minutes prior and sent two trucks to the building. They arrived just before the explosion.

The fire department was on the scene 2 minutes later.

ABC reports that two off-duty FBI agents and an off-duty New York Police Department officer were among those injured.

“This is a tragedy of the worst kind because there was no indication in time to save people,” New York City Mayor Bill de Blasio told the press Wednesday afternoon.

Kate Shindle, an actress and resident of East Harlem, woke up to the explosion and tweeted: “It blew the doors open on my building, two blocks away and around the corner. Shook the ground all the way to second avenue.”

ABC has obtained a video of the immediate aftermath of the explosion, taken by a witness.

Anthony Ferguson, 58, reported the explosion to police after it happened. He lives in the neighborhood.

“It was a quick boom,” Ferguson told Business Insider. “I saw a guy walk in and then fly in the air backwards. It looks like pressure blew him back.”

“There was pure black smoke,” he added.

Photos and videos have been coming in from Twitter and Instagram users:

— Adnan Islam (@orangeadnan) March 12, 2014

The Associated Press has also shared these images of New York Fire Department firemen extinguishing the 5-alarm fire:

For more on this story and to view all the videos go to: http://www.businessinsider.com/reported-harlem-explosion-2014-3#ixzz2vrZC6ve3

Related story:

Incredible images show what Harlem building looked like before and after it exploded

By Pamela Engel from Business Insider

ABC News and the Wall Street Journal have incredible before-and-after shots of the Harlem building that exploded early Wednesday because of a gas leak.

Three people died and at least 64 were injured in the explosion. Nine people are still missing.

The blast brought down two buildings at 1644-1646 Park Avenue in Manhattan. Power company ConEd recieved calls about a heavy gas odor 15 minutes before the explosion and sent two trucks to the building.

Reuters and the Associated Press have more images from after the explosion:

PHOTOS:

REUTERS/Brendan McDermid New York City Firefighters dig through rubble at an apparent building explosion fire and collapse in the Harlem section of New York, March 12, 2014. Harlem building explosion

AP Firefighters work the scene of an explosion that leveled two apartment buildings in the East Harlem neighborhood of New York.

REUTERS/Brendan McDermid New York City firefighters work at the site of a building explosion and collapse in the Harlem section of New York.

For more on this story go to: http://www.businessinsider.com/what-harlem-building-looked-like-before-and-after-it-exploded-2014-3#ixzz2vrQPqARC