The horrific mass shooting at a Midtown office building on Monday was the deadliest gun attack in the Big Apple in 25 years. Shane Tamura gunned down four innocent people — including an NYPD cop and a business executive — before turning the gun on himself late Monday.

There was a massive police response in Midtown Manhattan after a gunman opened fire inside an office building at 345 Park Ave. New York City Mayor Eric Adams said a NYPD officer, three civilians and the suspected gunman are among the dead.

Police have lined up four rows deep to pay respects to a fellow officer who was among the victims of a gunman's rampage at a Manhattan office tower.