The glittering skyscraper where hundreds work became the scene of New York City’s deadliest gun attack in 25 years when a man entered the lobby and started shooting.

The deadly Park Avenue shooting happened at one of the the most exclusive addresses in Midtown Manhattan — the “Blackstone Building," which is home to financial giant Blackstone, the NFL and accounting firm KPMG among a slew of other corporate names.

A gunman opened fire at 345 Park Avenue, home to the NFL’s headquarters, killing four people including a police officer and a Blackstone executive. Authorities say the shooter left a note claiming he had CTE,

Five people were shot and four killed by the 27-year-old gunman Shane Tamura, when he opened fire inside an office building at 345 Park Ave. on Monday evening. Among the victims were a Police Officer,

A 27-year-old man wearing body armor and carrying an M4 assault rifle shot and killed four people, including an off-duty police officer working security in a Midtown Manhattan office building, officials said during a press conference Monday evening.

NEW YORK (Reuters) -A spokesman for audit and advisory firm KPMG said in a statement the office at 345 Park Avenue will be closed on Tuesday, after a shooting in the building on Monday evening that left four dead, including a Blackstone executive.

Wesley LePatner, Senior Managing Director of the investment management company Blackstone, has reportedly lost her life due to a fatal shooting on Monday.

Shane Tamura, the Park Ave. gunman who killed an NYPD officer and three others before taking his own life, left behind a suicide note saying he suffered from CTE, a brain injury often linked to playing football, police sources said Tuesday.

Nearly 24 hours after a deadly Midtown mass shooting that left four people dead, including an off-duty police officer, detectives from the NYPD Crime Scene Unit combed through the plaza outside 345 Park Ave.