New York City is mourning an NYPD officer and three other people killed in Monday night's shooting inside an office building in Midtown Manhattan. Officer Didarul Islam was in uniform working as a security guard for a private company at the time of the shooting,

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 New York police officer, a “beloved” security guard and a senior executive with investment firm Blackstone were among four people killed Monday when a lone gunman stormed a sprawling office tower in Midtown Manhattan and opened fire.