Charlie Kirk is being remembered.

After the conservative activist was shot dead at age 31 while speaking at an event at Utah Valley University on Sept. 10, celebrities and politicians alike spoke out to pay tribute.

Kirk—who co-founded the conservative youth advocacy group Turning Point USA—was about 20 minutes into a presentation at the Orem, Utah, school when a suspect fired a gunshot from a building about 200 yards away, a spokesperson for the university told NBC News.

The political activist was taken to a hospital shortly after, but President Donald Trump confirmed he had died later that day.

“No one understood or had the heart of the youth in the United States of America better than Charlie,” the 79-year-old wrote on Truth Social on Sept. 10. “He was loved and admired by ALL, especially me, and now, he is no longer with us.”

Offering his condolences to Kirk’s wife Erika Frantzve Kirk, with whom he shared a 3-year-old daughter and a 15-month-old son whose names have not been shared publicly, Trump added, “Melania and my sympathies go out to his beautiful wife Erika and family. Charlie, we love you!”