An amateur boxer in the United States who collapsed during a weekend fight has died.

The Grand Forks Herald reports that North Dakota boxer Jerimiah “J.J.” Moen died on Wednesday morning at a hospital.

The 29-year-old Moen collapsed after the first round of a scheduled three-round, super-heavyweight Golden Gloves fight Saturday in East Grand Forks, Minnesota.

Moen’s uncle, Mike Sweeney, says the family learned this week that Moen had “serious trauma” to his brain from previous injuries, including concussions.

Moen had remained unconscious and in critical condition since the fight.