[UPDATES BELOW] An explosion in East Harlem, caused by a gas leak, led to the collapse of two buildings. [Update:] Three people have been confirmed dead (see more below).

The FDNY confirms that a building at East 116th Street and Park Avenue has at least partially tumbled to the ground.

Huge explosion at east harlem. A building just completely exploded. pic.twitter.com/0sBuG5U0d0 — Adnan Islam (@orangeadnan) March 12, 2014

On my way to work and then BOOM! Building explosion collapse on 116th. NYC #explosion116 pic.twitter.com/4ZIrnoyiET — Juan A. Vazquez (@madebyjuan) March 12, 2014

Photos from the scene show billowing smoke and general mayhem. As of right now, no injuries have been reported. [SEE UPDATES BELOW]

Update, 10:05 a.m.: Metro-North trains in the area were halted because of debris on tracks. NBC reports that some passengers were ordered off the train at 125th Street.

CBS has a live stream from 1646 Park Avenue, where the collapse occurred. The station reports that two buildings were involved, and that there have been reports of 11 minor injuries so far, a number that's expected to grow.

Gothamist executive editor Jen Chung, who is currently at 116th and Madison Avenue, reports that the air is so smokey that that visibility is reduced to less than a block.

One building appears to have burned completely to the ground.

Exclusive photo up close of scene of Manhattan/ Harlem explosion fire. pic.twitter.com/NoKzBmo7hy — Shimon Prokupecz (@ShimonPro) March 12, 2014

The FDNY tells us that several patients are being treated at the scene, but that the extent of injuries is still unknown. The Daily News reports that the fire initially began around 9:31 a.m. in the Absolute Piano store, located on the building's ground floor. Here's a photo of the building before it was reduced to rubble:



(Google Maps)

Update, 10:56 a.m.: Witnesses say a Spanish Christian church was one of the buildings destroyed. Carmen Vargas-Rosa, a woman involved with the church that's been at the location for 70 years, tells CBS 2 there was a gas leak several months ago that was repaired by Con Ed. There were several floors of residential apartments above the ground floor church, and four of the tenants remain unaccounted for as of 10:55 a.m.

"I thought the world was coming to an end," Ruben Santiago, who lives across the street, tells CBS 2. "The walls were shaking, everything."

Local resident Mukhlesur Rahman, who lives on 58 East 117th Street, tells us he "woke up to the building shaking felt like earthquake. Windows were blown out, glass was on the floor." Rahman said he saw smoke and fire, and then a wall collapsed.

Anjelica Avilez, 18, was in her apartment at 75 East 116th when the explosion occurred. She said she was alone with her dog when the explosion occurred and at first she couldn't get out the apartment door because it was jammed. Her stepmother, who was on a bus at 125th Street and raced home, was able to get her out using a key. "I was having an anxiety attack," Avilez added.

Update, 11:03 a.m.: The NYPD says there's no indication that the collapse was an act of terrorism. CBS2 is now reporting a total of 16 injuries, with one in critical condition.

Update, 11:23 a.m.: The NYPD reports that one man has been pronounced dead, and that there are currently 17 other reported injuries. The collapse appears to have been caused by a gas explosion, with numerous witnesses claiming to have smelled gas around 15 minutes before the blast.

ConEd received report of gas odor around 9:15 a.m. from Park Ave. resident, spokesman tells us. ConEd crews arrived right after explosion — Andrew Tangel (@AndrewTangel) March 12, 2014

Department of Buildings records show that 120 feet of new gas piping was installed at 1644 Park Avenue in June.

Update, 11:56 a.m. Another person has been pronounced dead, the New York Times reports, bringing the total fatalities to two, with at least four others hospitalized in critical condition.

Update, 12:13 p.m. A spokesperson for Con Edison tells us they received a call at 9:13 a.m. from a resident at 1652 Park Avenue complaining of a strong gas odor, who noted that the smell could have been coming from outside the building. Crews were dispatched at 9:15 a.m., and arrived just after the explosion occurred. As of now, there's no indication that the gas pipe installed at 1644 Park Avenue in June is to blame, though a full investigation will be conducted.

The building is served by an 8-inch low pressure gas main, the spokesperson said, and crews at the scene are checking the gas lines and working to isolate any leaks.

Update, 1:57 p.m.Mayor Bill de Blasio announced at a press conference today that the number of people injured has increased to 22, with two people currently hospitalized with life-threatening injuries. Five others have serious, but non-life threatening injuries, while 15 others sustained minor injuries.

Update, 7:15 p.m.: A third fatality has been confirmed by the authorities. In addition to the three deaths, 27 people were injured: Two were critically injured with serious injuries; five have serious, non-life threatening injuries and 20 have minor injuries. No FDNY or other first responders were injured. The mayor's office said, "Nine occupants of the buildings are unaccounted for according to Fire Marshals and the NYPD. Anyone attempting to locate family or loved ones that may have been in the immediate area should contact the Unified Victim Identification System at 311, which is active."