Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday.

Family, friends and members of the New York City Police Department will come together on Thursday for a funeral for the "hero" officer who was one of four people killed in the Midtown Manhattan mass shooting.

Officials said the gunman fatally shot himself after his attack, which set off a chaotic scene that rippled out into the heart of Manhattan during rush hour.