Manchester Grammar pupils 'poisoned' during scuba diving lesson
Twelve pupils have been treated for carbon monoxide poisoning after becoming ill during a school scuba diving lesson, police have said.
The group of boys at Manchester Grammar School in Fallowfield were taken to hospital at about 15:10 BST on Monday.
Eleven were later discharged following treatment, while one, aged 14, remained in hospital in a stable condition.
Greater Manchester Police are investigating whether carbon monoxide was present in the boys' air tanks.
Officers are also working with the Health and Safety Executive to ensure "there is no wider risk to the public or diving community", a force spokesman said.