This is a breaking news story. For latest updates, please go to our live blog. An NYPD officer and at least four other victims were killed in a shooting at an office skyscraper in midtown Manhattan Monday evening,

Multiple casualties as gunman opened fire in the lobby of the midtown Manhattan building on Park Avenue that is home to the Blackstone investment firm and other corporations before moving to other floors.

A 27-year-old man wearing body armor and carrying an M4 assault rifle shot and killed four people, including an off-duty police officer working security in a Midtown Manhattan office building, officials said during a press conference Monday evening.