Seven teenagers, a grandfather in his 60s and a woman in her 70s are known to have died - including two teenagers pulled from the water today.

The man, in his 60s, suffered a 'cardiac arrest in the sea' after heroically trying to help two relatives at Tregirls Beach, near Padstow, at around 3.50pm yesterday.

The perils of swimming in open water have been laid bare following the deaths of five children with a drowning prevention charity demanding schools get water safety on the…