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

Thousands of familly, friends and colleagues are expected to gather to mourn the NYPD officer killed in this week’s Manhattan office attack at a funeral on Thursday, a day after another grieving family laid their loved one to rest,

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.