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

Police Officer Didarul Islam, a father of two with a baby on the way, was one of the four people killed by Shane Tamura inside 345 Park Ave. on Monday.

Didarul Islam, 36, was a father of two, with a third on the way, and was working a second job as a security guard at the building where shots rang out.