The Cruel World Music Festival had to be suddenly evacuated due to a thunderstorm that made a surprise appearance at the Rose Bowl Saturday night.

FThe festival has been postponed until further notice. Please evacuate the festival site immediately. Use the nearest emergency exits. Stay tuned for updates," the festival tweeted,

The National Weather Service says they are monitoring the storm system, which is making its way between Mt. Olive and Pasadena and Monrovia.