when does caroline become a vampire

Caroline becomes a vampire in the TV series "The Vampire Diaries" during the transition that begins in 2010, initiated by Katherine Pierce. Specifically, Caroline was injured in a car accident and taken to the hospital, where Damon Salvatore fed her his vampire blood to save her. However, before the blood could complete its work, Katherine smothered Caroline to death. Caroline then woke up in the vampire transition, confused and starving for blood. She completed her transformation into a vampire after drinking human blood she stole from the hospital. This event happens in the early part of season 2 of the show. Damon initially tries to kill her to prevent the complications of her vampire life, but Stefan intervenes and helps Caroline adapt to her new vampire existence. The transformation takes place on February 26, 2010, according to the series timeline.