A 17-year-old girl died at Kendal Calling festival in the early hours of Sunday morning.
Police said emergency services were called to the festival site in the Lake District in Cumbria at 2.13am, following reports of the girl suffering a "medical episode".
Despite the best efforts of emergency responders, including the administration of CPR, she was pronounced dead at the scene, Cumbria Constabulary said.
The girl's family have been told and are being supported by specialist officers.
Enquiries into the circumstances surrounding her death are ongoing.
Police are keen to speak to people who were in the area of the festival's Calling Out tent and the Big Wheel at around 2am.
They also want to speak to a group of women who directed emergency personnel to the girl after becoming concerned for her welfare.
A festival spokesperson said in a statement: "The team at Kendal Calling are deeply saddened by the passing of a festival attendee in the early hours of Sunday morning following a medical episode.
"As soon as the individual became unwell, they were immediately attended to by our on-site security and medical teams.
"Paramedics and medical personnel provided emergency care at the scene and did everything they could to help.
"We extend our deepest sympathies to the individual's family, friends and loved ones at this incredibly difficult time.
"We are supporting the relevant authorities and will continue to assist them with their investigation."
The four-day festival, which continues Sunday (2 August), is being headlined by acts Biffy Clyro, Wolf Alice, Two Door Cinema Club and The Kooks.
Growing year on year since its launch in 2006, Kendal Calling takes place annually at Lowther Deer Park, near Penrith and Hackthorpe.
(c) Sky News 2026: Teenage girl dies at Kendal Calling festival
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