Local authorities told NBC News they were responding to reports of shots fired at the Bronx Lebanon Hospital Center in New York City on Friday afternoon.
A NYPD spokesman said the suspect is dead from a self-inflicted wound. Police said the suspect was a former employee of the hospital.
The spokesman said the gunman killed one victim and wounded at least five others.
A law enforcement official told the Associated Press that the gunman was seen wearing a lab coat and concealed a rifle inside of it.
A person on the hospital staff told NBC New York that the facility is under lockdown.
Images captured by local television crews showed police sweeping the roof of the building and the area with their guns drawn.
There were also reports of a smoke situation on one floor of the hospital. The fire department said they recieved a call at 2:55 p.m., ET.
Video taken by people nearby showed heavy police presence.
This is breaking news. Please check back for updates.
— Reporting by NBC News and NBC New York.