The funeral is being held in south Dublin of the five members of the Connors family, who perished in the Carrickmines fire.
Hundreds of mourners have gathered at the church of the Ascension of the Lord in Balally, to remember Thomas, Sylvia, Jim, Christy and baby Mary.
The President and Taoiseach are represented by their Aides de Camps, and various politicians are also attending.
Parish priest of the Travelling people, Fr Derek Farrell spoke of the "tsunami of grief" the families have endured.
Fr Farrell said: "You, the Connors, Lynch and Gilbert families know too well that anguish of waiting for loved ones to be given back to you, of waiting to lay your loved ones to rest."
In his role as priest for the Travelling people, Fr Farrell took the opportunity to praise the good will of the community in the wake of the tragedy, but said it needs to be a new beginning.
He also spoke of his hope for the future.
Thomas and Sylvia, and three of their children, five-year-old Jim, three-year-old Christy and five-month-old Mary perished in that fire, leaving two of their children Michael and Tom orphaned.
Thomas and Sylvia are described as a "match made in heaven", and "the best father and mother that any children could ask for".
Following requiem mass, the funeral cortege will travel to Wexford this evening to the Church of the Assumption.
After a prayer service tomorrow at noon, the family will be laid to rest at Crosstown Cemetery.