Sebije Nelovic always felt safe at 345 Park Avenue. For nearly three decades, the Albanian native cleaned the ritzy Manhattan skyscraper that housed several corporate headquarters in one of New York’s toniest neighborhoods.

In a lengthy statement shared by the 32BJ Service Employees International Union on Thursday, 65-year-old Nelovic described coming face-to-face with Shane Devon Tamura, the 27-year-old gunman who authorities say entered the office tower shortly before 6:30 p.