On Friday, all of New York City watched in horror as a gunman invaded Bronx-Lebanon Hospital. Here's what we know so far:

According to law enforcement officials, the shooter was 45-year-old Dr. Henry Bello. Bello used to work at the hospital, but resigned in 2015 so he could avoid being fired. The hospital's website says that he practiced family medicine.

Bello entered the hospital with a rifle in the afternoon—the first gunshots were reported at 3 pm. He was wearing a white lab coat. The most recent reports have Bello wounding five people and killing one, a woman whose name is not yet being released, but who is believed to be a fellow doctor.

Bello fatally shot himself on one of the upper floors of the hospital—it is variously being reported as the 16th or 17th.

The incident is not being treated as terrorism-related. Instead, it is being treated as workplace violence.

Stay tuned as more details become available.