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

A New York police officer, a “beloved” security guard, a young Cornell graduate and a senior executive with investment firm Blackstone were killed Monday when a lone gunman stormed a sprawling office tower in Midtown Manhattan and opened fire.

The shooting occurred in the lobby of 345 Park Avenue on East 52nd Street, an office building that records indicate is home to the NFL, Blackstone and KPMG.