Arthur Moreira, 13, was at home with his dad on May 5 when the accident occurred, before being rushed to the hospital in critical condition.
The boy's grieving father, Jose Henrique Goncalves, told local media that he picked up his son from school because he had a broken foot. While at home, he heard one shot and then saw his son fall down bleeding.
"I picked him up from school, he went to his room to change his clothes and came back bleeding from his room," Mr Goncalves, from Rio de Janeiro, Brazil, said. "He was the pride of his father, mother, and siblings. He idolised his siblings and was a boy who always gave his best."
Boy used lighter to heat up bullet
It's not known how the boy came to be in possession of the bullet but investigators believe he may have used a lighter to heat it up. The bullet, they believe, then exploded, injuring the teen in the neck.
The investigators drew their conclusions after finding a cartridge case, a lighter, and a burnt piece of paper in the teen's bedroom.
Following the incident, the boy was taken to hospital alive but in critical condition. He ended up dying after suffering a cardiorespiratory arrest.
'He was a good boy,' says devastated mum
His devastated mum, Aline Goncalves, told local media her son "was a good boy, intelligent and talkative". "It's unbelievable," she said of her son's death.
"Everything he did, he did with dedication," she added. "If he had to surf, he surfed well, if he had to swim breaststroke, he did it, everything, skateboarding, he wanted to be the best."
One of Arthur's friends wrote online: "May God comfort his family, the Rio skate community is in mourning."
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