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

A man stalked through a Manhattan office tower firing a rifle, killing four people, including a New York City police officer, and wounding a fifth before taking his own life, officials said.

Familly, friends and colleagues are preparing to mourn the NYPD officer killed in this week’s Manhattan office attack at a funeral Thursday, less than two days after hundreds stood in salute as his casket received a dignified transfer to the mosque where he’ll be remembered.