A 14-year-old boy has died after collapsing during a PE (physical exercise) lesson at a secondary school in Essex.
The year 10 pupil at the Barstable School, Basildon, died later in hospital.
The boy, who has not yet been named, was warming up for the lesson on Tuesday at about 1030 BST when he suddenly collapsed.
He died later in Basildon General Hospital.
A spokesman for Essex County Council said the pupil's death was completely "out of the blue", as he was fit and healthy.
All pupils have been told of the tragedy and the local authority has arranged for grief counsellors to go to the school, to support children and staff.
The school remained open for the rest of the day - but some students chose to go home.