He died from brain trauma sustained in a knockout loss against Charles Conwell.
Day was born to Haitian immigrants in Freeport, New York, and was the youngest of four sons.
His father was a doctor who used to box as a child, while his mother, Lyssa, was a translator at the United Nations.
He also captured the regional WBC Continental Americas light middleweight title.
[8] Conwell posted an open letter online that expressed his sorrow and regret.