The young Irish student who lost his life after jumping into a river during a neknomination drinking challenge was "terrified" of water and unable to swim.
Patrick Byrne (26) – who tried to save his brother Jonny (19) from the flood-swollen River Barrow – said he could not understand why the young hurler leapt into the water.
Patrick believed the internet craze sweeping the country is the "biggest form of bullying" seen so far and blamed much of the craze on "peer pressure".
"A friend of Jonny's, he stood up against it last week and said he was not going to do it. He was bullied, slated and called a coward for the week," Patrick said.
He urged people to be aware of the dangers of the growing trend and to boycott the craze.
"We had no idea what Jonny was going to do, we thought he was going to drink. We knew he was nominated and would drink the drink," said Patrick.
Along with his girlfriend, he saw his younger brother leap into the water on Saturday evening at Milford Bridge in Carlow – less than a kilometre from their home.
"We can't understand it. He couldn't swim, he was terrified of water, even back in primary school," he said.
The family has launched a campaign to stop neknomination, which involves people posting an online video of themselves downing a strong drink, sometimes combined with a stunt.
His father, Joe Byrne, explained how the dare or 'nomination' appeared to have gotten out of control last Saturday night.
"Jonny was doing this dare with a drink and he was with my son Patrick. Patrick turned away for an instant and within that instant he had his tracksuit off and went flying by him, and the next thing he landed in the river," he said.