The pair were among 71 people who died in the Grenfell Tower fire in Kensington, West London, during in the early hours of June 14 last year. They were poisoned by carbon monoxide as the block turned into an inferno, sparked by a fridge fire on the fourth floor, but almost certainly fanned upwards by the block's newly installed exterior cladding.
Looking at those Instagram images today, Gloria and Marco's parents can draw a little — just a little — comfort, knowing how happy they were in their final weeks.
"It was the first time they had lived together," Marco's mother Daniela says. "For them, it was the start of a wonderful life together."
Daniela, 58, and her husband Giannino, 62, came over to visit last April and say the couple's excitement was palpable.
"They were living in a beautiful skyscraper with amazing views. I saw how happy they were," says Daniela. "Marco cooked, Gloria kept the place tidy. They'd made lots of friends." But of course, tingeing those happy memories is fury and almost unbearable grief that these two promising young lives were snuffed out so cruelly.
An inquiry report into the tragedy is imminent, but already the combustible exterior cladding, installed during a NZ$20 million refurbishment the previous year, has been widely criticised. The Grenfell management has also been accused of ignoring warnings about blocked fire escapes, faulty extinguishers, electricity power surges and a lack of sprinklers.
Equally to blame, say Daniela and Giannino, was the stay put advice given to residents of high-rise flats in cases of fire — a line slavishly adhered to by the fire brigade emergency controllers on the night of the blaze.
Although the London Fire Brigade has never provided a full explanation of its advice with regard to Grenfell, telling tower block residents to stay put is standard practice because the perceived wisdom is that fires in individual flats can be contained.
Official guidance is that it is safer to remain in a flat than to venture into a potentially lethal smoky stairwell. What's gut-wrenching for Marco's parents is that they've learned how a mother and a son, who also lived on the 23rd floor, survived because they ignored this advice.
Speaking exclusively to the Mail, Marco's parents described the heartbreaking series of phone calls with their son and his girlfriend in the early hours of that fateful morning, as they waited for help.
At first, the young couple reassured the pair that they would be fine, but they started to sound increasingly worried. Then came their last, horrifying calls where they said how much they loved their parents and shared their final tragic goodbyes.
Their bodies were found in an embrace, shielded from the flames by falling rubble.
"Marco was always someone who followed the rules," says Daniela.
"He felt a great deal of responsibility for Gloria and at that moment he did what seemed to be the best thing. All his friends said it was impossible that he would go against the advice of the fire brigade."
Describing the moment she was told about his death, Daniela says: "It's as if they flayed me alive. The pain was so bad. You can't imagine it. In life you expect accidents or illness, but not this.
"I wake up remembering everything. I dream of Marco. Last time I dreamed of him, he said, 'I'm coming home'. For a while I didn't want to live. Even now, I hope to join him."
Marco's father has similar feelings.
"When I go to sleep or wake up, it's terrible. I feel lonely, vulnerable ..." he says, before trailing off.
Daniela, a civil servant in education, and Giannino, a retired regional director of a business information company, raised Marco, their only child, in a detached villa in San Stino di Livenza, a small town 36 miles north-east of Venice.
He excelled at school and won a place at the University of Venice to study architecture. It was here he met Gloria, a young woman from the Veneto region of northern Italy.
Gloria, the only daughter of Emanuela and Loris, was on the same course as him. Soon the pair became inseparable.
Like many young middle-class Italian students, the couple were unable to live independently because of a lack of money, so were forced to stay at home with their parents.
After graduating with a Master's degree, Marco worked at an engineering studio for less than NZ$800 a month before he and Gloria decided to seek their fortune in London.
They arrived in March, secured a privately rented flat on the top floor in Grenfell, and enrolled on an intensive language course for two months to perfect their English.
Gloria quickly found work with Peregrine Bryant Architecture Building and Conservation, in South-West London, while Marco worked as an architect at Creative Ideas & Architecture Office (CIAO for short), based in East London.
"After all those years of studying hard and earning hardly any money, he had finally arrived in life. At that point I was so happy for him," says Daniela.
"Marco and Gloria hadn't spoken directly of marriage, but when I told her that I wished I had more children when I was younger, she said, 'Don't worry, I'll have grandchildren for you'. I was waiting for all this to happen ..."
A month later, at the end of April, Daniela and Giannino decided to visit the lovebirds.
"We went to Buckingham Palace, the Tower of London and Wimbledon. They dedicated those three days to us and showed us every corner of London. We saw it with different eyes."
Breaking down in tears, Daniela recalls: "At the end of the trip, when I said goodbye to get on our flight, we hugged strongly — it was a hug that said so many things. Looking back, it was a premonition. There was a love and a communication between us which was difficult to explain. It was the last time we saw our beloved son."
Marco and Gloria were planning to return home to Italy on June 21 for Marco's birthday. The family had organised a week of celebrations and invited all his school and university friends to the family home. Daniela had bought the ingredients for his favourite risotto dish in preparation.
A week before Marco's return, Daniela received a panicked, early-morning phone call from Gloria's mother, telling them she'd had a call from her daughter saying their tower block was on fire.
Coincidentally, the Gottardis were awake as they were preparing to catch an early flight from Venice to Sicily for a short holiday. Forgetting all about their trip, they called Marco, who initially tried to reassure them that British firefighters had managed to get the blaze under control and were in the process of rescuing everyone from the tower.
Daniela huddled around a phone in their living room in a state of quiet panic, desperately trying to believe that their son was safe.
Over the next 25 minutes, Marco's stoic attempt to spare his parents from worry began to fail.
"I asked him, 'Why don't you try to leave?' and he said, 'There is smoke everywhere, it is too hot,'" Daniela recalls.
"They tried to open the door to their flat, but the smoke began filling their living room. That was at about 2.45am. That was when the fire brigade told them to leave, but it was too late. I had a sense things were getting worse and at 3.10am I felt a big pop in my ears as if I was on an plane. It felt like something had happened and I believe that's when Marco and Gloria died."
Desperate for information, they turned on Sky News and saw the inferno engulfing Grenfell.
"Our son tried to convince us he would be saved, but when I saw the burning tower on TV I knew it was the end," Giannino says.
"He knew he had to die, but didn't want to tell us. Marco's attempt to protect us was typical of him — he was a gentleman until his last breath."
Moments later, Giannino got a text message saying he had a voicemail. It was from Marco, who said: "I cannot understand why the line is constantly failing. I love you, both you and my mother."
For Daniela, the feeling that she was losing a son she had nurtured from a difficult pregnancy to become a self-assured young man was too much to contemplate. She collapsed on the sofa as Giannino continued to call their son's mobile number over and over for another 30 minutes. It rang, but no one answered.
"By 4.30am, I knew that there was nothing that could be done to save him," he said.
Gloria spent her final moments on the phone to her mother, Emanuela.
In a desperately poignant final call, she told her mum: "I am so sorry I can never hug you again. I had my whole life ahead of me. It's not fair. I don't want to die. I wanted to help you, to thank you for all you did for me. I am about to go to heaven, I will help you from there."
In those final minutes, Gloria said, "Mama, I am dying", before reciting the Hail Mary prayer.
While Marco's parents were under no illusion that he had survived, without official confirmation, they clung to a shred of hope.
They were buoyed by the efforts of Marco's cousin Pamela Pizziolo, who lived in London and was organising search parties. She told her aunt and uncle that a group of their son's friends visited a string of hospitals in the hope that he and Gloria had been rescued. But they were never found.
The following day, Giannino gave a short account of the final phone calls to the Italian media and said: "We're just hoping for a miracle."
But that miracle never arrived. Two days after the blaze, both Marco and Gloria were officially named on the list of the dead.
In following days, the Gottardis' grief turned, in part, to incredulity when it emerged that catastrophic safety failings were being blamed for the fire's rapid spread.
"I am angry with the people who decided to use this cladding, who didn't put in safety procedures or sprinklers," Daniela says.
"If any one of these would have worked, then my son would be alive.
"I place enormous blame on those responsible for the safety of the hundreds who lived in the building. How did they judge this was acceptable? Who decided to use these materials?
"London is a global city — a city you expect so much of, where you would never expect this to happen. These actions brought about the destruction of so many families."
Giannino believes the glaring safety errors were "generated by human greed to save a few thousand pounds".
"The renovation took place a year before the fire — to criteria which don't exist anywhere in the world," he said.
"The building was like a torch. How is this possible? I could understand it if the works were done 50 years ago, but this was two years ago."
An inquiry is expected to start before the June anniversary. Daniela and Giannino want "criminals named" and companies forced to pay damages.
In their attempt to establish exactly what happened, they travelled to London two months ago. They say rumours of the advice by fire chiefs to stay put were confirmed by a senior coroner.
"To hear it from someone in authority was incredible," Giannino said. "This advice was madness. This was the last link in the chain of the causes of this tragedy."
The couple's pilgrimage offered what Giannino calls a "partial consolation". They learned that Marco and Gloria were not burnt alive as they feared, but died from carbon monoxide poisoning.
Marco's passport, driving licence, credit cards and even some cash were found intact and sent to his parents, along with his partially burnt clothes.
To this day, Daniela carries a small piece of a trench coat that Marco bought in London.
In an attempt to come to terms with their loss, the couple have immortalised Marco and Gloria as fairytale heroes in a children's book they have published.
In the story, Marco is a knight who must save Gloria, a princess who lives in a tower threatened by a fire-breathing dragon.
However, the book — The Knight And The Princess — gives the couple a happy ending, where they live together happily surrounded by butterflies and dragonflies.
"I got rid of the way Marco and Gloria died, because otherwise I wouldn't survive the pain. I wouldn't wish it on any mother," says Daniela.
The book, Daniela explains, helps her, as a mother, live with losing her only child in such a cruel way.
"The only thing left to do is to carry forward their message of goodness, willing and love," she said. "I'll do that until the end of my days.
"If you use these things, and love, which makes the world go round, then maybe these bad things won't happen any more."
