At about 12:20 a.m. Sunday, police responded to a 911 call of an assault in progress in front of 250 Hayward Street.
Investigators believe the two brothers were playing in an adult soccer game at the school. Shortly after midnight, 911 was called. Both brothers were found outside the school with multiple stab wounds.
The brothers were then transported to Woodhull Hospital, where one died of his injuries.
He has been identified as 31-year-old Delvin Martinez, who suffered stab wounds to the torso and neck.
Delvin's 29-year-old brother is listed in critical but stable condition with stab wounds to the torso, neck and face.
There have been no arrests as the investigation continues.