Logan Davidson, 15, died Wednesday afternoon at University Hospital in San Antonio, the San Antonio Express News reported. Investigators said an autopsy was scheduled for Wednesday.
Another student at Canyon High School in New Braunfels was arrested after Tuesday's fight and charged with assault. He was being held in the Guadalupe County Juvenile Detention Center.
Andrew Kim, the school superintendent in the Central Independent District, said counselors would be at the school to help students.