Investigators are reviewing building permits for an Anaheim high school auditorium stage that collapsed late Saturday, injuring two dozen students.
Officials said they hope to determine what restrictions were placed on the stage at Servite High School.
About 250 students were performing at the private Catholic high school Saturday when the platform gave way, injuring 24 students and stunning the crowd.
A video posted to YouTube showed a large crowd packing the stage, dancing, shouting and waving pom-poms in the air before the platform suddenly collapsed.
The part of the stage that gave way was an extension, which was added in 1996, said Lt. Tim Schmidt of the Anaheim police department.
"It's a very nice, well-maintained building," Schmidt said. "But clearly there was way too much weight.
"That's what it looks like."
It's likely permits for the stage would have included weight restrictions, but investigators are still reviewing city documents to determine whether those restrictions were in place and if so, what they were, Schmidt said.
Anaheim police, fire officials and building inspectors are investigating the collapse, as is the Diocese of Orange.
The performing students were from Rosary High School, an all-girls Catholic School in Fullerton and were taking part in an annual "Red & Gold" school spirit show at Servite.
In an update posted on the Rosary High School website, officials said the students were performing for a large crowd of alumnae, faculty and family members.
Two dozen students who complained of pain and possible broken bones were taken to local hospitals.
All of them had been released by Sunday, Schmidt said.