The New York City office building that was the site of a mass shooting Monday had significant security measures in place.

Businesses across the U.S. are reevaluating security after a shooting at a New York City office building raised concerns about workplace safety

The deadly violence at a Park Avenue tower is weighing heavy on the minds of office workers in Midtown Manhattan.

The man who killed four people in the New York City skyscraper that is home to NFL headquarters carried a note blaming the league for his mental health problems

The gunman who opened fire in midtown Manhattan on Monday, killing four people before turning the gun on himself, left a note mentioning “CTE” several times, officials familiar with the investigation told NBC News.