Multiple casualties as gunman opened fire in the lobby of the midtown Manhattan building on Park Avenue that is home to the Blackstone investment firm and other corporations before moving to other floors.

Investment company Blackstone said its Manhattan offices will be closed Tuesday after Monday's mass shooting that killed several people, a source familiar with the matter told Reuters.

The 27-year-old man who shot and killed four people at a Midtown office building on Monday carried a note in his pocket, police sources told ABC News.

Wesley LePatner, a Blackstone executive with deep ties to Jewish communal organizations in New York City, was killed in the Monday shooting at the firm’s Midtown headquarters, the company confirmed on Tuesday.

New York City Mayor Eric Adams said Tuesday that a gunman who killed four people at a Manhattan office building was trying to target the headquarters of the National Football League but took the wrong elevator.

In the aftermath of a shooting that took place inside a Midtown skyscraper that houses Blackstone and NFL headquarters Monday, July 28, Intelligencer reported that the crazed gunman appeared to have targeted Blackstone. Three people were shot, including a cop who died. The shooter is also dead.