INDIANAPOLIS (AP) – Indiana Gov. Mike Pence is promising a thorough state investigation into a stage collapse at a central Indiana high school that left more than a dozen students with minor injuries.

Pence said Friday the State Fire Marshal's office, Indiana State Police and Indiana's workplace-safety agency are working with Westfield officials to investigate Thursday night's collapse at Westfield High School during a musical performance.

The governor says state officials “are thoroughly investigating the causes of this incident and will make every effort to prevent this or worse from happening in the future.''

Video of the incident shows a stage over an orchestra pit suddenly give way, sending students plunging into that pit.

Pence said he's “relieved beyond words'' that no one was killed or seriously injured in the collapse.