Both boys are believed to be from Ennis.
Two teenagers were airlifted to hospital on Thursday afternoon following a mishap which left them in difficulty while swimming.
Gardaí and Emergency Services were called to an incident which occurred at Knockanean Quarry lake at Knockanean, Ennis, Co Clare following reports that two people were in trouble in the water.
According to Gardaí, the alarm was raised at about 3.30pm.
Two units of Ennis fire service, including their water rescue unit, were then dispatched to the incident along with Gardaí and ambulance paramedics, following reports that assistance was needed.
A rescue helicopter from Shannon was also mobilised, and two 15-year-old boys, both believed to be from Ennis, were taken from the lake.
Efforts were made to resuscitate them once they were brought ashore.
Both boys were then airlifted to Limerick Region Hospital at about 5pm. Their conditions have been described as critical.
