(CNN)The family of Nathan Valencia, the University of Nevada Las Vegas (UNLV) student who died days after a charity boxing match, said his death "could have been avoided."
Cynthia Valencia told CNN's Brianna Keilar Monday she was worried when her son first mentioned he was going to participate in UNLV's Kappa Sigma fraternity's "Fight Night" November 19.
"But he kept telling us 'no, this is for people who didn't have prior boxing experience,' because he never was a boxer. He truly was just doing this because it was for a charity," she said.
Nathan, 20, died four days after collapsing at the end of the fight. He was a member of Sigma Alpha Epsilon, another fraternity.
Nick Lasso, an attorney for the Valencia family said, "This was an event that was known to the university, it's been held many times in years past."
According to an online flyer for the bout, the event was a fundraiser for Center Ring Boxing, a Las Vegas-based organization that establishes youth boxing programs for area children and their families.
Lasso said it appears safety protocols were not followed, claiming there were no professional referees or paramedics on-site. "It just appears that there were safety failures, every single step of this process," he said.
CNN has reached out to the university, the fraternity and Center Ring Boxing for comment, but has not heard back.
Cynthia Valencia said, "In the past, they've always had professional referees," but said "we've heard this time they just pulled some random guy from Kappa [Sigma fraternity]... that's what we believe."
Cynthia added after her son collapsed, he was lying "on the floor, waiting for paramedics for about 15 minutes 'cause they didn't have paramedics on standby at the site."
In a statement over the weekend, UNLV and the Kappa Sigma fraternity released separate statements saying they were saddened over the tragic loss of Valencia, with the university noting the event was held off-campus.
Valencia's official cause of death has not been released.