Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday. The injured victim was an employee at the NFL, according to NFL Commissioner Roger Goodell. Here's what we know about the four people killed:

The victims of the Manhattan office building shooting are identified as NYPD Officer Didarul Islam, Blackstone executive Wesley LePatner, Cornell grad Julia Hyman and security officer Aland Etienne.

A vigil will also be held Friday night for NYPD Officer Didarul Islam so the community can come together in mourning. CBS News New York's Christina Fan reports.