Natalie DiBlasio

USA TODAY

Two high school students were hospitalized in New Zealand after their necks were cut by a prop razor blade during their opening night performance of Sweeney Todd: The Demon Barber of Fleet Street, a story of a barber who uses the tools of his trade to murder his customers.

Stephen Cole, the headmaster of Saint Kentigern, told TVNZ that the prop had been used throughout rehearsals since January, despite some concerns from parents. Now, the school is taking heat for not opting to use a plastic prop instead of a dulled-down metal razor.

"The importance of making the show authentic, making these boys and girls — some of whom wish to pursue acting as a career, it was deemed important to make it as realistic as possible," Cole said, noting that the blade had been filed down and covered in duct tape. "It was a razor that you would expect to see in a production of Sweeney Todd."

Both of the injured boys are 16 years old. The BBC reported that they were in a stable condition.

Saint Kentigern canceled the Thursday performance of the show, according to its website.

The school is following a script of Sweeney Todd that is meant for younger audiences. Still, the school notes on its website that the content is mature: "While some of the more disturbing scenes and text in the original version have been removed, the premise (that Sweeney Todd kills people and turns them into pies) remains a central part of the story line."

Cole tells TVNZ: "Maybe next year we'll do something that's more general."

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