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.

FBI Deputy Director Dan Bongino said agents from the bureau’s New York field office were responding to the area to provide support.

Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday. Among the victims was an officer who was a dad of two with a third on the way. Here's what we know about the victims: Officials identified the others killed in the shooting as two men and a woman,