Charlie Kirk, a conservative activist and close ally of President Donald Trump, was shot and killed Wednesday at a Utah college event in an act that drew renewed attention to the threat of political violence across the United States.

People were seen running, as screams rang out of the Sorensen Center courtyard where the youth organization Turning Point USA was holding the event. Law enforcement had cleared the area that included the white tent where Kirk was sitting when he was shot.

The death was announced on social media by Trump, who praised the 31-year-old Kirk, the co-founder and CEO of Turning Point USA, as “Great, and even Legendary.”

The suspected shooter has not been arrested, Orem, Utah, Mayor David Young said. A person who was taken into custody by law enforcement at the university where Kirk was speaking was not the suspect, according to a person familiar with the investigation who was not authorized to speak publicly.