GONZAGA College Dublin has expressed its "deep shock" at the death of two long-serving priests who taught at the institution.
The fee-paying, Catholic boys' secondary school announced on Monday afternoon that Fr Joe Brennan SJ, who taught history, and Fr Kennedy O'Brien SJ, an English teacher, have passed away.
In a statement, the school said: "It is with deep regret that we inform you of the passing this morning of two long-serving members of staff, Fr Joe Brennan SJ and Fr Kennedy O'Brien SJ.
“As you can imagine, the college community is in deep shock at the loss of these men who gave their lives in service of Gonzaga College and its students.
"They will be greatly missed and each in his own way is irreplaceable.
"Eternal rest grant on to them, O Lord, and let perpetual light shine upon them."
Gonzaga, which is under the trusteeship of the Jesuits, said it would provide further details as soon as they become available.
Fr Brennan taught at the school for more than 40 years and was continuing to play an active role in school life despite being retired.
He is understood to have been hospitalised in the days leading up to his death, according to the Irish Times.
Fr O'Brien was responsible for fostering the well-being of students in his role as Gonzaga's "spiritual father".
He passed away unexpectedly at his home.
Both men were among the few teachers remaining at the school who were also members of the Society of Jesuits.
Founded in 1950, Gonzaga educates around 550 students at its campus in Ranelagh, Dublin.
The fee-paying college, which is one of five Jesuit schools in Ireland, charges its students fees of around €6,000 (£5,300) per annum.