Sir – Quarry operators know that the warmer weather heralds an increase in young people and adults entering quarries uninvited with potentially tragic consequences.

Sadly, there have already been four deaths in non-operational quarry lakes during the hot spell we are now enjoying.

With the school summer holidays about to commence, the Mineral Products Association (MPA) are keen to ensure that these risks are better understood and to appeal to parents to ensure that their youngsters are not tempted to enter into local quarries uninvited.

Our Stay Safe campaign is supported by the parents’ of teenagers who have died, they believe that their sons might still be alive today if they had understood the risks they were taking.

Quarry lakes may look inviting but the temperature of the water can be icy cold in places, extremely deep, conceal unexpected currents, pumps or other obstacles hidden beneath the water. The impact that cold water can have on one’s body can result in even very experienced swimmers suddenly finding themselves in trouble and the water can be difficult to exit.

Quarry faces can be unstable and collapse when standing close to the edge or expose people to the risk of being hit by falling boulders if they are attempting to climb the face or standing beneath it.

Sand stockpiles can collapse or shift, burying and suffocating individuals.

Settling ponds may look like firm ground, particularly after the surface has been drying over a prolonged period, but can give way and suck you down like quicksand.

Quad and trail biking in quarries exposes riders to the risks from unstable ground suddenly collapsing or being hit by plant or machinery.

I would urge parents and others to view and share our Facebook page Stay Safe Stay Out of Quarries with others. Our message and the message from the parents of the boys who have been killed is simple - unless you are invited on an organised visit by the quarry operator – Please Stay Safe ...Stay Out of quarries.

Elizabeth Clements, Mineral Products Association