The office building, located at 345 Park Avenue, houses some of the country’s top financial firms, including Blackstone, and the National Football League. According to the company's website, Blackstone stands as the world’s largest alternative asset manager, managing over $1 trillion in assets under management.

An active shooter incident occurred in Midtown Manhattan, New York, officials said. Here's what to know about 345 Park Ave.

Officials said the gunman fatally shot himself after his attack, which set off a chaotic scene that rippled out into the heart of Manhattan during rush hour.