Watch : UFC Fighter Allan “Puro Osso” Nascimento Dead at 34The UFC has lost a fighter. Brazilian athlete Allan "Puro Osso" Nascimento died of an apparent heart attack on Aug. 3, the organization shared on X. "This morning, Monday, August 3rd, our beloved flyweight fighter, Allan Nascimento, was found unresponsive after suffering an apparent heart attack in his sleep," read a statement from the UFC. Known as “Puro Osso" ("All Bones") because of his lean size growing up, Nascimento signed with the UFC in 2021 and was 4-2 in six appearances, according to ESPN. While he hailed from São Paulo, Brazil, Nascimento noted that Las Vegas—where the UFC is based—had become his "second home," sharing on Instagram July 21, "Every visit reminds us why."