Andrew Piskadlo was standing in the middle of a campus amphitheater on Wednesday, waiting to debate Charlie Kirk about the Eighth Amendment, when a single shot rang out.

“It was surprising, and no one really got down until the people in front of the stage did,” Mr. Piskadlo, 28, of Salt Lake City, said in a phone interview. “People got down in waves.”

He had been in line at a campus event at Utah Valley University, waiting to speak to and debate Mr. Kirk, as students typically do in the so-called “Prove Me Wrong” debates that Mr. Kirk, a right-wing activist, hosts.

Mr. Piskadlo, who estimated that he was about 80 feet away, recalled that Mr. Kirk had been responding to a question about transgender mass shooting suspects at some point before he was shot.

When the shot rang out, he said he dropped first but did not run. He said he did not see Mr. Kirk get shot. He estimated that the shooting occurred just minutes after the program began, shortly after noon local time.

Mr. Piskadlo, said he was active in Utah politics, said the setup of the amphitheater struck him as unsafe before the event. Despite a heavy security presence, he noticed “there were a lot of ledges, points where this could happen,” he said. “This seemed really preventable. I’m kind of angry at the organizers.”

When the shot rang out, he said he saw people starting to get down and take cover.

The crack of the shot “wasn’t nearly as pronounced,” he said, which may explain why not everyone in the crowd dropped immediately.

“I’m just hoping Charlie is OK,” Mr. Piskadlo said.