[4][5] Keenan died during a rescue in an attempt to assist freediver Alessia Zecchini to the surface from a depth of 50 metres in Dahab's Blue Hole in 2017.
He had studied microbiology at Trinity College, but had lived for about eight years in Egypt,[3][7] where he was a freedive instructor.
He later relocated to Dahab, became a freediving instructor, and trained hundreds of students in Egypt, Spain, and the Philippines.
Zecchini was attempting to cross the Blue Hole on a single breath, but became disorientated when Keenan was 20 seconds late to arrive at a meeting point.
[2] According to the Irish Independent, "Keenan suffered an in-water blackout in the last 10 meters of the ascent.