Bruno Ferreira couldn't believe it when the face of his former soccer student appeared on TV screens around the world.
It had been just nine days since Adul had gone missing, yet he couldn't believe the boy's transformation.
"I was in shock when I saw the first images. Adul was always a very strong boy, I was amazed to see how he – and the entire team– were looking so weak and malnourished," Mr Ferreira told SBS Portuguese*.
"They were always very strong: they played soccer, they rode their bikes, but in the images they looked so weak. That was a blow for me, I was shocked."
In the now famous footage of the world's first glimpse of the group, Adul had been the one to reply to the British diver who discovered them, confirming in English that all 13 of them were alive.
The moment Bruno Ferreira (second from left) and Adul’s family heard that the entire football team and their coach had been found alive. Source: Supplied
On the Sunday the boys had gone missing, Mr Ferreira had learnt from his own football students that Adul and his team, the Wild Boars, were trapped in the Tham Luang cave which was just five minutes from the young coach's own house.
At the entrance to flooded cave where the boys' bikes were still parked, he had joined dozens of distraught family members looking for the 12 missing children and their 25-year-old assistant coach.
Originally from Petrópolis, Rio de Janeiro, Bruno came to Thailand in 2012, to volunteer and help build the community. Source: Supplied
"I went there to help the family I knew, and stayed there every day," Mr Ferreira said.
"Those were tough days filled with tension and distress; the atmosphere was of great concern, for no one knew where the boys were."
He spent the next two weeks with the family of Adul, offering support and helping wherever he could around the camp that was hastily erected. He remained there as the news spread to the world, as hundreds and then thousands of volunteers, rescuers and foreign reporters flocked in, and he was there when the rescue operation began.
Adul's letter that was sent out to his family while he was still trapped in the cave. Source: AAP
"At first they were all very confident, but very tired, especially Adul’s father," Mr Ferreira said.
"He was there sleeping in chairs for nearly two weeks. I was with him and remember his face was so faint. Despite the hope, the expectation from wanting to see his son leaving the cave, had exhausted him.
"But he has always maintained his confidence, even when the Thai diver died."
Nearly two weeks after the Adul and the other boys became trapped in the cave with their assistant coach, the boys were able to get letters out to their families that were subsequently broadcast to the world.
Adul's note read: "Don't worry about us now. I miss you all. I would like to go home as soon as possible."
After living in Mae Sai near the cave for the past five years, Mr Ferreira had come to know the cave well.
"I've been there in the broadest part of the cave, called the 'hall'," he said.
"A lot of people visit the cave, the team went there other times, because it is a very beautiful place. Having said that, I had not yet met anyone who had gone to the end of the cave, it's more than 10 kilometres."
Originally from Brazil, Mr Ferreira moved to Thailand in 2012. He knows the local community well after working at the school and volunteering as a coach on the football team. Long before the 12 boys and their coach made international headlines with the traumatic incident, the local community had been supportive and tight-knit, Mr Ferreira said.
"Everyone here stopped everything they were doing to volunteer," he said.
"Groups went up the mountains to try to find other entrances; people left everything to go there, to offer massages, to cook and offer food, to assist where possible.
"It's really cool to see how the whole Thai community comes together and helps each other."
