The lobby of 345 Park Avenue will reopen for the first time since last Monday's mass shooting that left four innocent victims dead.

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.

Kelley Mack, an American TV actress who appeared in AMC’s “The Walking Dead,” “9-1-1” and “Chicago Med,” died on Aug. 2. She was 33. Her family reported in a statement that Mack died in her hometown of Cincinnati after a battle with glioma of the central nervous system. Mack graduated from Hinsdale Central High School …