Puerto Rican boxer Prichard Colon's death has brought back the controversy surrounding the injuries he suffered in his last fight with Terrel Williams in 2015. Colon was rendered vegetative by Williams' punches to the back of his head- a condition that did not change, despite periodic improvements, in the next 11 years of Colon's life.

Prichard Colon died at 33 on August 13. (Prichard Colon/Instagram)

Immediately after the fight, Prichard Colon spent 211 days in coma. Though doctors were able to save his life, he never returned to normal. For the rest of his life, he continued to battle complications arising from the illness.

What exactly happened on the night of October 17, 2015, that left Prichard Colon vegetative? This is a key question as the fight in Virginia did not end with an injury, and Prichard Colon kept on till a confusion over the gloves led to his disqualification. He even walked away from the ring on his own, telling his mother at one point that he felt "dizzy."

Also read: Did Terrel Williams apologize to Prichard Colon's family for head punches? Revisiting dispute amid boxer's death

"Those punches landed where the spine meets the brainstem, and the skull barely covers that spot," Williams wrote on X. "The bleed that started there had nowhere to go. Trapped blood builds pressure. Pressure kills brain tissue.

"Brain tissue does not come back. Surgeons saved his life that night, but no treatment in medicine could return what the bleed took. He spent 221 days in a coma and the next decade unable to walk or speak, while his parents cared for him around the clock.

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"Prichard did what a fighter is supposed to do," he continued. "He reported the fouls to the one person who could stop them. It didn't save him. That part has never left me.

"Boxing learned from him. In 2016 the WBC put a zero-tolerance rule on those punches and named it after him. Fighters are safer today because of what he lost. Once brain damage runs this deep, we cannot treat our way out of it. Prevention is the only cure."

A cause of death for Prichard Colon was not announced. His father and former coach, Richard Colon, who revealed the news of his death, only stated that he is in a "happy place now."