According to the Mahabharata, Karna received three major curses that contributed to his death: 1) Parashurama's curse that he would forget his skills when needed most, 2) A Brahmin's curse that his chariot wheel would sink into the earth during battle, and 3) Mother Earth's curse that she would not support him when he needed ground stability. These three curses converged during the Kurukshetra war.