The death has taken place of Ron Clifford, an Irish man who survived the 11 September 2001 terrorist attacks in New York, in which his sister and niece died.
Mr Clifford, who was from Cork, was on the ground floor of the World Trade Center when the first of the 9/11 attacks occurred there. He survived uninjured.
However, his 44-year old sister Ruth Clifford McCourt and her four-year old daughter Juliana died on board one of the planes that crashed into the World Trade Center.
Mr Clifford campaigned for many years to have those who masterminded the terrorist attacks brought to justice.
He died suddenly at his home in Connecticut in the US last night.
"The justice system here has just prevented it and it's just going around in a circle for years and years," he told RTÉ News. "I hope in our lifetime we will get our day in court."
He said he was angry at the failure to bring those responsible for the attacks to justice. His family was deeply affected, but learned to cope over the years.
"The world has changed. The catastrophic event that we as a family have gone through - I think we have lived our lives since. I think that is the positivity that we give as a family," Mr Clifford said.
Ms Clifford McCourt and Juliana were buried in Cork, along with Ruth's husband and Juliana's father, David, who died in 2013.
Funeral arrangements for Mr Clifford have not been finalised.
