Police are warning parents and teenagers that a viral TikTok game could trigger major emergency responses after a Sydney TAFE campus was plunged into lockdown when a student was spotted carrying a water pistol. The alarm was raised at Campbelltown TAFE on Tuesday afternoon when a 16‑year‑old girl walked through the grounds holding the brightly coloured water pistol — later revealed to be part of a TikTok challenge known as “Senior Assassin”.