Sean McGrotty (49), his two sons Mark (12 and Evan (8), their 59-year-old grandmother Ruth Daniels, and her daughter Jodi-Lee (14) died on Sunday after a family day out turned into an unspeakable tragedy.
Their Audi Q7 slid off a slipway at Buncrana Pier in Co Donegal and was submerged in Lough Swilly. In the midst of the panic Sean handed his four-month-old daughter Rioghnac-Ann out a window, where she was rescued by passer-by Davitt Walsh.
The infant is recovering with her mother, who was at a family event in England when the accident happened.
Bishop of Derry Donal McKeown said these were not days for words but rather to show support by being with the family.
"I have visited, expressing sympathy to Louise and the family circle who have lost so many family members," he added. "There are no adequate words in the face of such pain."
Church of Ireland Bishop of Derry and Raphoe Ken Good said "the sense of loss was inconceivable". "It is impossible for most of us to comprehend the depth of heartache that the bereaved are experiencing," he added.
Among those paying tribute yesterday was Manchester United star Wayne Rooney. "Devastating news about young Mark, Evan & family from Derry," he wrote on Twitter.
Mourners have been expressing their sorrow in books of condolence at St Joseph's Church in Galliagh and Holy Family Church in Ballymagroarty, where all five victims will be brought for a joint funeral service.
Less than a year ago Derry mayor Elisha McCallion put her chain of office on Evan and Mark after they crossed the line at the Walled City Marathon mini race in Guildhall Square. Yesterday she signed their book of condolence.
Typical of the messages was one simply signed 'The Harkin Family' which read: 'Five angels have arrived in Heaven to watch over us. God Bless you and your family during this time. Thoughts and prayers are with you.'
Bouquets of flowers were left on the railings of St Eithne's Primary School where Evan was a pupil. Principal Terence McDowell said: "As a community we are torn apart by the tragic events of the weekend.
"Evan was a beautiful, much-loved child who added a great deal to the lives of all he touched here in St Eithne's."
Philip O'Doherty, chairman of Derry City Football Club, issued a statement on behalf of the side where Josh Daniels, who has lost his mother, sister, brother-in-law and two nephews, is a player.
In it he said: "We are conscious of the depth of his loss. Inadequate as it is, everyone at the club wants to assure him that they will be with him in the coming days and, more importantly, in the weeks and months that lie ahead."
Before the Dail in Dublin held a minute's silence in their memory, acting Taoiseach Enda Kenny said the magnitude of the horror put everything else in perspective.
"Our hearts go out to them and what is a devastating impact on the lives of the extended family," Mr Kenny said.
"We all know in our own lives the numbing grief that comes with the loss of a loved one. In these circumstances, however, this is a particular and deepest grief, that the tranquillity and beauty of a sunny spring Sunday was shattered by this tragedy."