A schoolgirl who collapsed during a trampolining session died of a rare heart condition, an inquest has found.
Lily Webster, a pupil at Stowmarket High School, collapsed suddenly at Mid Suffolk Leisure Centre in January.
The coroner said: "Her classmates saw her do some somersaults successfully but she then stopped. She put her hands to her head and said 'oh my God'."
First aiders and then paramedics were called as people feared the 15-year-old was suffering some kind of seizure.
Despite attempts to resuscitate her, she died at the leisure centre.
Speaking after her death, Stowmarket High School headteacher Keith Penn paid tribute to the schoolgirl saying: "Popular, active, bright and with a very wide circle of friends, Lily will be desperately missed by students and staff and all those who knew her."
At first her death was a mystery and tests were carried out on her brain, heart and blood.
Consultant cardiologist Dr Mary Sheppard, from the Royal Brompton Hospital, later concluded Lily died as a result of sudden adult death (SAD) syndrome - an unpredictable attack in people whose heart is structurally normal.
The condition kills around 500 people in England each year.
Lily's parents, Richard and Melanie Webster, were not at the inquest but in a statement read out at the hearing described her as a girl who made friends easily and loved life.