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

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.

At the height of the evening rush, a man double-parked his BMW on Park Avenue, calmly strode across a public plaza with an assault-style rifle in his hand, stepped into the lobby and opened fire. Glass shattered in the lobby and bodies lay still. Office workers sprinted out of the building or scrambled for cover.

Police lined the streets of New York City to pay their respects to fellow officer Didarul Islam, who was among the four victims of a gunman’s rampage Monday at a Manhattan office tower.