A shooter entered a bank in downtown Louisville and killed at least five people on Monday.

Police say the shooter was killed soon after the shooting began, NBC News reported.

One of the six people injured was an officer from the Louisville Metro Police Department, per The Washington Post.

According to NBC News, “The shooting is being described as a case of workplace violence, perpetrated by an employee who struggled with mental health issues.”

The gunman started firing in a conference room in the Old National Bank, and witnesses at the scene described the shooter being “armed with a long gun,” per ABC News.

The bank shares a building with other businesses and residences, per the Post.

“He just started shooting,” Troy Haste told ABC Louisville affiliate WHAS. “Whoever was next to me got shot. Blood is on me from it.”

According to The New York Times, police responded to a call about a shooting, and “they encountered active gunshots still being fired inside the location,” Paul Humphrey, deputy chief of Louisville Metro Police Department, said.

Kentucky Gov. Andy Beshear was on his way to the scene and tweeted, “Please pray for all the families impacted and for the city of Louisville.”