UPDATE 7 pm EST: The injury total is now at 12, reports USA Today (http://usat.ly/16v0wpK).
The blast caused the partial collapse of the first floor, said Assistant Chief Robert Boyce. The cause was not immediately known.
The New York Daily News cited an apparent natural gas explosion. NBC News, citing an unidentified law enforcement official, said the blast may have been caused by a severed gas line in the basement. WABC-TV reported that the rear of the building may have been under construction.
Original Story: At least nine people were injured after an explosion caused a collapse in New York City's Chinatown in Manhattan.
The explosion Thursday is thought to have been due to natural gas, according to a Daily News report (http://nydn.us/1av59aU). Three people were reported critically wounded.
Firefighters responded after an explosion ripped through a first-floor apartment in a five-story building. The first-floor ceiling collapsed after the blast.
Photos showed Fire Department of New York (FDNY) firefighters tended to injured victims.
Two firefighters also suffered minor injuries.
For more details and photos, visit http://nydn.us/1av59aU.
For training info on similar incidents, consider Building Construction Concerns for Firefighters: Structural Collapse, Drill of the Week: Structural Collapse Rescue, and Firefighter Response to Natural Gas Leaks and Emergencies.