Primary school children were rushed to hospital after being poisoned by chemicals in a pool during swimming lessons.
Thirteen kids, aged four and five, were treated after they started 'vomiting violently' and had trouble breathing during the lesson at Chesham Leisure Centre in Buckinghamshire.
One mother said she arrived at Gateway School in Great Missenden, Buckinghamshire, to see 'four ambulances surrounding a coach'.
A teacher told her a number of children were 'vomiting violently' within minutes of beginning the class at School.
The mum said: "They took a decision to get them off site as quickly as possible and got them back to school where they had ambulances waiting. For many, it was their first swimming lesson. All were discharged, but their parents are furious."
Greenwich Leisure Limited, which runs the centre, apologised.
A spokesman said: "Water circulation in the swimming pools failed to restart after a planned power cut which resulted in a strong smell in the pool area.
"Emergency procedures were followed, the area was immediately evacuated and a number of pupils were taken to hospital for precautionary medical checks. None required further medical attention.
"A full investigation has now taken place and it was found that all the proper procedures were followed."