Days after a fraternity charity boxing match, a college student died from injuries he allegedly sustained during a fight.
According to KLAS 8 News Now, 20-year-old Nathan Valencia, a junior at the University of Nevada, Las Vegas (UNLV), participated in Kappa Sigma Fraternity's Fight Night.
A flyer on Instagram listed the Nov. 19 match between Valencia and another person as the main event at the Sahara Events Center in Las Vegas, with proceeds benefiting Center Ring Boxing, a youth boxing club.
The Valencia family told the news outlet that Nathan sustained fatal brain injuries and collapsed following the fight, resulting in his death on Nov. 23 — four days before his 21st birthday.
"Kappa Sigma Fraternity is greatly saddened by the loss of Nathan Valencia at the University of Nevada, Las Vegas. Our deepest condolences, thoughts and prayers are with the Valencia family and the entire UNLV community," the organization said in a statement.
In a statement obtained by PEOPLE, lawyers for the Valencia family from the Richard Harris Law Firm described the family as "heartbroken over the loss of Nathan."
"Our preliminary investigation reveals mistakes were made and safety precautions overlooked. We will be completing a full investigation to determine how UNLV and the Kappa Sigma Fraternity could allow and promote an event like this to take place," read the statement.
"College students should not be placed in a situation where they are pitted against each other for combat. 'Kappa Sigma Fight Night' is an event that has been held annually and was well known to both UNLV and the national Kappa Sigma Fraternity," the statement continued.
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"We will leave no stone unturned to determine how a 20-year-old ended up in a school-sanctioned amateur fight that cost him his life. The family has asked for privacy during this time to grieve," the statement concluded.
While speaking to 8 News Now, Valencia's longtime friend, Joe Castro, referred to the event as an "underground fight club."
He also alleged there were no medical professionals or qualified referees at the boxing match. Shortly after Valencia collapsed, Castro said a brawl broke out "while Nathan was just in the ring, like, laying there. It was ridiculous."
UNLV President Richard Whitfield issued a university-wide email acknowledging the "tragic incident" on Friday, PEOPLE confirms.
"We are shocked and heartbroken as we mourn the loss of one of our own," Whitfield wrote in part. "Coping with the loss of life is always difficult, especially under these circumstances. UNLV is committing all available resources to review the incident and determine how off-campus events like these can be as safe as possible."
"Our deepest sympathies go out to his family, friends, and loved ones," he continued. "I am sure words cannot describe their feeling of grief and emptiness. They are in our thoughts during this very difficult time. The Rebel community shares their loss."
A GoFundMe with a goal of $100,000 has been set up to help the Valencia family with medical and funeral expenses.