The father of an "intelligent, caring" 18-year-old girl from Somerset who died after taking horse tranquilliser drug ketamine has described how "one act of stupidity has destroyed our family".
Ellie Rowe, from Glastonbury, took the class C drug while attending the Boomtown Fair festival in Winchester, Hampshire, last summer.
An inquest heard that the teenager was volunteering as a steward for Oxfam at the event with a friend, Stephanie Peirce, on August 8 when she snorted a line of ketamine powder having drunk a few cans of Carlsberg lager during the day.
In a statement read to the Winchester inquest, Miss Peirce, also 18, described how she fell asleep in their tent after taking the drug and came around to find Miss Rowe unconscious.
She said: "Ellie was unconscious, I tried to wake her up but she wouldn't, at the time I thought she felt a bit cold, I got a bit worried so I tried different methods of waking her up, speaking loudly, shaking her.
"I stumbled out of the tent and I asked the first person I saw to help me because I couldn't wake her up."
The inquest heard that on-site paramedics attempted to revive Miss Rowe, including giving her an emergency tracheotomy to aid her breathing, until an ambulance arrived and took her to the Royal Hampshire County Hospital in Winchester where she was pronounced dead.
Pathologist Dr Adnan Al-Badri told the hearing that toxicology tests showed that Miss Rowe had 2.14mg of ketamine per litre of blood in her system which was the second lowest recorded fatal dosage of the drug recorded.
He said that she had 88mg of alcohol in 100ml of blood which is 1.1 times the drink-drive limit.
Dr Al-Badri explained that the use of alcohol exacerbated the danger of taking ketamine.
He said: "In combination, she actually caused more damage than if she had taken ketamine alone."
Coroner Sarah Kirby recorded a narrative verdict which stated that Miss Rowe died as a result of alcohol and ketamine toxicity and central nervous system depression having taken ketamine and alcohol.
She said that Miss Rowe had snorted approximately 200mg of the drug from two wraps of ketamine that the pair had bought from a "friend of a friend" at the festival.
She said: "Ellie was a young girl who would have had no idea whatsoever that what she did would cause her death.
"She was 18, it is not that she was an habitual drug user, she thought it would be fine, she didn't think about it."
Speaking after the inquest, Miss Rowe's family said they wanted to warn others of the dangers of taking ketamine, especially in combination with alcohol.
They also called for it to be reclassified as a Class B drug to reflect the fatal consequences that can occur from taking it.
Her father, Anthony Rowe, a self-employed businessman and caretaker, said: "She was very responsible, it's an absolute tragedy, it was one act of stupidity and that can destroy a family.
"This wasn't some major drug use."