Four days after being knocked unconscious in a super welterweight title fight, Patrick Day, a former New York Golden Gloves champion and Long Island native, died on Wednesday.

Day, 27, had been in a coma since Saturday night, when he fell to the canvas and hit his head after his opponent, Charles Conwell, a 2016 Olympian, landed several blows in the 10th and final round of their U.S.B.A. fight in Chicago.

His death was announced by Lou DiBella, the promoter for both Day and Conwell.

“It becomes very difficult to explain away or justify the dangers of boxing at a time like this,” DiBella wrote on his website on Wednesday. “This is not a time where edicts or pronouncements are appropriate, or the answers are readily available. It is, however, a time for a call to action.”