Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday. The injured victim was an employee at the NFL, according to NFL Commissioner Roger Goodell. Here's what we know about the four people killed:

Blackstone Inc.’s Wesley LePatner, a top executive in the firm’s $325 billion real estate business, was killed Monday when a gunman opened fire at the company’s Manhattan headquarters. She was 43.

Workers in business attire were seen piling couches up against their office door -- with the towering furniture reaching the ceiling.