An annual concert at University of California, Irvine, ended in mayhem late Friday after one of the performers caused a stampede and then allegedly waved a gun around. The show was canceled after midliner Famous Dex, who was opening for rapper YG at Shocktoberfest, reportedly jumped into the audience area, sparking a stampede that organizers said constituted a safety hazard. As students flooded out of the arena after being told the event was canceled, some of them reportedly swarmed Famous Dex’s car. The rapper reportedly pulled a gun out as fans surrounded his vehicle, and another male companion in his car allegedly pulled a gun on students and told them to “get off the fucking car,” according to a witness cited by New University, the official campus newspaper. The incident prompted university police to send out an emergency alert warning students about a man seen with a gun in the area. Famous Dex later bragged about the chaos on social media, saying, “I just shut the show down. And it was all positive vibes.” The rapper later posted a Snapchat video with a girl identified as a UCI student, and the same girl was reportedly shown in his hotel room in his late-night Instagram stories.