His comments marked the beginning of two weeks of poignant tributes from family and friends of the 72 victims as the first phase of the public inquiry gets under way.
Almost one year on, bereaved family and friends will paint a picture of the loved ones they lost, telling their stories to the retired judge chairing the probe, Sir Martin Moore-Bick.
Pausing often as emotion overcame him, Gomes said: "On the night we managed to escape the horrific fire at around four in the morning. That same evening, we found out that we had lost our son, Logan, in the hospital."
The raw pain of the family's grief was evident as they spoke. Gomes said his other children were "physically okay and we try to move on".
"This was our little star, Logan Gomes," he said, visibly distressed, as a picture of an ultrasound of Logan was shown on screen.
Gomes said he had been planning adventures to go on with his unborn son, and saw him as a "future gaming buddy" and "superstar" who would be his partner on the Xbox.
His two young girls were incredibly excited about the arrival of their baby brother and wanted him to sleep with them in their beds rather than the nursery that he had decorated.
The words "twinkle, twinkle, little star, do you know how loved you are?" were displayed on screen, which, Gomes said, had been on the wall of the child's room-to-be.
"It was our way of showing how much we loved our son, Logan," he told the hearing.
"Already we had so much planned for him in terms of adventures and what we would to together."
The girls were so excited they did not care about the summer holidays, but they had planned to go to Disneyland as a family of five this summer.
He said: "Everyone was so happy that Logan was going to be born. no one more so than my wife Andreia. As you can see from the photos she was just glowing with happiness. The pregnancy suited her, and all her friends, family were all very happy that Logan was being born. We cried, during the reveal party that we had, when I found out it was a boy."
Breaking down, he thanked Andreia for her "strength and courage" before the couple shared an emotional embrace.
"That was absolutely beautiful, thank you," said Bernard Richmond QC as the tribute ended.
Opening the inquiry, Sir Martin said: "In terms of loss of life the fire was the single greatest tragedy to befall this city since the end of World War II.
"The sight of the building engulfed in flame is indelibly printed on the memories of those who experienced an event of unimaginable horror."
He added: "When we die, we live on in the memories of those who knew and loved us. It is fitting therefore that the opening hearings should be dedicated to the memory of those who died.
"They will be remembered by the words and pictures chosen by the people who knew them best and loved them most, their families and friends."
The fire swept through Grenfell Tower in west London on June 14 last year. Some families have chosen not to take part in the commemorations.
The commemorations are taking place at the Millennium Gloucester Hotel in south Kensington, a new venue closer to the Grenfell community.
Private rooms, quiet areas and a prayer room will be available for the bereaved, survivors and residents, and there will be counselling and NHS support.
The rest of phase one of the inquiry will take place at Holborn Bars in central London, where several procedural hearings have already happened.
The probe is believed to have the largest number of core participants to date, with more than 500 survivors, bereaved families and friends, and members of the North Kensington community participating.
