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The officials say eight other people were struck by bullets but those injuries are not believed to be life threatening.
The officials say the gunman previously worked at a store inside the landmark skyscraper. The shooting happened at about 9 a.m. Friday at 34th Street and Fifth Avenue.
The law enforcement officials spoke on condition of anonymity because they were not authorized to publicly discuss the matter.
Federal officials say the shooting isn't related to terrorism, and a guard at the landmark said it didn't involve the parts of the building where tourists gather to visit the skyscraper.