Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday.

Wesley LePatner, 43, was among the four people killed by a gunman who stormed the Park Avenue building where she worked on Monday.

Bankers and traders returned to work on a somber Tuesday morning in Midtown Manhattan, New York's financial epicenter, one day after a shooting that killed four people, including a senior Blackstone executive.