LOUISVILLE, Ky. (NewsNation) — A Louisville bank employee armed with a rifle opened fire at his workplace Monday morning, killing five people while livestreaming the attack on Instagram, authorities said.

The shooting, the 15th mass killing in the country this year, comes just two weeks after a former student killed three children and three adults at a Christian elementary school in Nashville.

Louisville Mayor Craig Greenberg shared with NewsNation how he and his community are coping.

The interview has been edited and paraphrased for length and clarity.

NewsNation: Can you just put into words what the last 24 hours have been like for you, for this community and for the entire state of Kentucky?

Greenberg: Yesterday’s tragic event — every act of gun violence is heartbreaking for me and for our entire city. But I’m also thankful — thankful for the officers who responded bravely and quickly, heroically to deal with the situation that was unfolding. They truly save lives. The doctors and nurses at the University of Louisville Hospital saved lives yesterday as they do every day. But I’m also tired. I think our community is tired. We’re tired of these acts of gun violence plaguing our city, plaguing too many cities and towns across our country.

NewsNation: You have been through a workplace shooting before. Take me through your emotions yesterday. How triggered were you when you got the call that this was happening here in your city?

Greenberg: I was driving into my office downtown when I heard way too many sirens, and at the same time, seeing an alert on my phone that there was an active shooter. So my heart certainly sank. When I saw the address, I know a lot of people who work in this building. I lost a very close friend yesterday. Many others around the city lost their close friends, their loved ones. So, it was a difficult day. But I knew that we needed to stay focused on addressing this situation and working to continue to bring the city together to heal with strength and heal with a commitment to action.