Two teenage boys have died on the Greek island of Ios.
They have been named as Andrew O’Donnell and Max Wall, from Ireland.
They completed their studies at St Michael’s College secondary school in Dublin this year, which said it was a “day of immense sadness”.
The school said Max was a “constant source of positivity” and described Andrew as “popular” and a “committed” footballer.
It said in a statement: “We have been notified of a devastating loss from the class of 2023, with the passing of Max Wall.
“He was extremely popular with staff and students alike, and a fantastic supporter of our teams during the various cup campaigns (as well as a great brother to past pupil, Charlie).
“Our thoughts are with Max’s family at this awful time and with his friends who have experienced such shocking loss over the last 24 hours.”
In an earlier statement, the school said Andrew was “not only a popular classmate and friend, but a proud and committed member of our football team”.
It added: “He was kind to those around him, honest in all of his endeavours, and a great brother to Rory.
“Andrew will be sorely missed by all who had the pleasure of knowing him.
“Our thoughts are with Andrew’s family and friends at this extremely difficult time.”
Students who would like to access support are being encouraged to contact members of staff.
Ireland’s Department of Foreign Affairs is aware of the case and providing consular assistance, a spokesman said.
“As with all consular cases, the department does not comment on the details of individual cases,” he added.