Quiñones had been facing Jose Munoz at Coliseo Elias Chegwin in Barranquilla, Colombia. Entering the fight undefeated, the two boxers were in a back-and-forth fight until the eighth round, when Quiñones was knocked down by a punch after showing wobbly legs.
Quiñones was reportedly taken out of the ring via stretcher. By Thursday, he was brain dead.
His brother confirmed his passing on Facebook, per ESPN:
"You went ahead of us my loving brother, now you are with your heavenly father, whom you adored and served, I love you my brother Luis Quinones, forever and ever in our hearts," Leonardo Quinones wrote.
The promoter of the fight, Cuadrilátero Boxing, released its own statement in Spanish on Instagram lamenting the death and saying they would continue to support the boxer's family as long as needed. A rough translation:
Cuadrilátero Boxing deeply regrets the death of Luis Quiñones, an exceptional, disciplined human being who always showed the greatest commitment to this sport.
Luis was passionate about boxing, so much so that he left his hometown, Barrancabermeja, to make his way in Barranquilla and become a professional athlete. His idol was Julio Cesar Chavez.
Since last Saturday we have been accompanying his family, his team, and the medical staff and we will continue to do so for as long as they require it.
In the same way, we thank the staff of the Clínica General del Norte, who during all the time did what was within their power and took care of Luis in the best possible way.
Per ESPN, Quiñones was diagnosed with a "neurological deterioration as a result of head trauma due to traumatic contusions" during surgery. Doctors also reportedly performed a craniectomy, a removal of part of the skull to accommodate brain swelling, after detecting a subdural hematoma.