Quarry water is a 'stone cold killer', according to the Department of Agriculture, Environment and Rural Affairs (DAERA).
In a statement this morning, DAERA call for people to "Stay out and Stay alive", as they warn of the dangers of swimming in disused quarries. .
In 2013 two local men drowned at an Annalong quarry.
Colin Polland, 39, and 15-year-old Kevin O'Hare perished in the tragedy at the Glassdrumman Road site during hot weather.
DAERA point out that as the Easter holidays and summer period approaches, the likelihood of good weather brings additional risks.
Parents are asked to speak to their children about the dangers that they are unwittingly subjecting themselves to when they visit disused quarries.
Director of Regulatory and Natural Resources Policy at DAERA, Dave Foster, said: “I would appeal to parents and young people to be aware of the dangers of disused quarries and not to enter any body of water.
"Quarries are not a playground and quarry lakes in particular, pose the greatest risk. They are often much colder than rivers, lakes and reservoirs as they can be fed by water sources that originate deep underground.
"A sudden plunge into cold water initiates a gasp response, which can cause drowning within seconds.
“After four minutes in cold water, poor blood circulation causes stiff fingers, reduced coordination and loss of strength.
"Swimming to safety and pulling yourself out of the water, or even treading water to stay afloat, may no longer be possible.
"Quarry water really is a stone cold killer. The message is clear. Stay out. Stay alive.”