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 executive was shot and killed in the lobby of the ritzy Park Avenue office tower when gunman Shane Tamura opened fire.

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.