A New York City office building where a gunman killed four people then himself has reopened a week after the deadly shootings. On Monday, workers trickled back into 345 Park Avenue in Midtown Manhattan, a skyscraper home to high-profile tenants including the NFL and asset management firm Blackstone.

Flags across New York are flying at half-staff to honor the victims of Monday’s deadly Midtown Manhattan office shooting, including an NYPD officer.