For a classroom of kindergartners in Russia, Santa is dead.

It all happened right before their little eyes, when 67-year-old Valery Titenko suffered a sudden and fatal heart attack during a performance at an elementary school in Siberia, the Moscow Times reports.

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“The man felt ill in the kindergarten, he was taken in an ambulance but died in the way to the hospital,” an unnamed source told sibdepo.ru, a local news site.

The Times explained the man was hosting the Christmas party as “Ded Moroz,” or the Russian version of Santa, as part of a Soviet-era tradition that also includes the fairy tale snow maiden Snegurochka.

Video of the incident shows Titenko chasing a classroom of costumed youngsters as they laughed and giggled, before abruptly standing upright, then falling backwards. A woman in what appears to be a clown costume rushed to his aid as students gathered around, laughing at what they undoubtedly thought was part of the routine.

The Mirror reports Titenko had complained of chest pains prior to the performance but didn’t want to let the kiddos down.

A spokesman for the Musical Theatre of Kuzbass, where Titenko was a fixture, told the news site his “health was not ideal” in recent years.

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“He had been through complicated heart surgery, but still performed on the stage and had been working at full capacity, not sparing himself,” the spokesman said.

The students in Siberia weren’t the only ones with a traumatic school Christmas this year.

A substitute teacher in New Jersey ruined the holiday for a classroom full of first graders earlier this month, which forced the principal at Cedar Hill School to send an apology home to parents, WIVB reports.

Parent Lisa Simek wrote on Facebook that the unidentified teacher told the kids Santa isn’t real and parents “just buy presents and put them under their tree.”

Simek said the teacher didn’t stop with Santa, either.

“She told them reindeer can’t fly and elves are not real (and) elf on the shelf is just a pretend doll that your parents move around,” she wrote.

“She did not even stop there: the tooth fairy is not real because mom or dad just sneak into your room in the middle of the night and put money under your pillow, same goes for the Easter bunny. She told them magic does not exist. There is no such thing as magic anything,” Simek wrote.

Principal Michael Raj apologized to parents about the teacher’s “poor judgement.” Montville Schools Superintendent Rene Rovtar also issued a statement that she was “troubled” and “disheartened” by the teacher’s comments.

“The childhood wonder associated with all holidays and traditions is something I personally hold dear in my own heart,” Rovtar wrote.

The superintendent later confirmed to USAToday that the teacher no longer works for the school district.