Why is the flag flying at half mast?

MARCH 27, 2023

A Proclamation on Honoring the Victims of the Tragedy in Nashville, Tennessee

Here is the link to the Proclamation:
https://www.whitehouse.gov/briefing-room/presidential-actions/2023/03/27/a-proclamation-on-honoring-the-victims-of-the-tragedy-in-nashville-tennessee/