Police said that 250 girls from Rosary High, Servite's sister school, were on stage for the "Red and Gold Rally," a musical theater event. The girls were dancing to Beyonce when the stage caved down the middle, sending some students 10 feet into the pit.
"They were on their final performance so everyone was jumping around like crazy, and then all of a sudden the very front row just completely fell under. We were all in shock," eyewitness Stephanie Stevenson told KABC.
The students sustained minor to moderate injuries, with the most severe being broken bones.
Though authorities are still trying to determine the exact cause of the collapse, Anaheim Police Department spokesman Lieutenant Tim Schmidt told reporters that "early investigations suggest the front of the stage gave out due to weight."