London's mayor, Boris Johnson, decided to pull a little stunt as part of an Olympic celebration.
He was supposed to zip line above Victoria Park while waving two union jack flags.
He did zip line for a while until he eventually lost his momentum and came to a complete stop, dangling above the crowd.
He took the whole incident surprisingly well.
Check out the video (above) to watch the mayor of London get stuck on a zip line. LOLz!