In the fifth season episode "The Ship", Muniz was part of an expeditionary team lead by Captain Sisko to survey heavy deposits of cormaline on Torga IV, an uninhabited planet in the Gamma Quadrant. During the mission, a Jem'Hadar attack ship crashed on the planet and the team went to investigate. While they were investigating, another Jem'Hadar ship arrived and destroyed the runabout in orbit, killing the three crew members aboard. A strike force then beamed down to the surface and attacked Captain Sisko's team, with Muniz taking a disruptor bolt to the leg. The team took cover inside the downed ship, but the team's medic had been killed and so Muniz could not be given proper treatment. O'Brien tore off scraps of his uniform to bandage Muniz's wound, but the Jem'Hadar disruptor bolt had an insidious side-effect: it left behind an anticoagulant in Muniz's system, preventing the wound from clotting. So even though Muniz was shot in a non-vital area, the anticoagulant ensured that it would be a fatal shot.
As Sisko, O'Brien, Worf and Dax struggled to get systems working inside the hot, dank ship, Muniz slowly bled to death. Worf suggested killing Muniz, that slowly and painfully slipping away was no way for anyone to die. O'Brien refused to do any such thing and he and Sisko kept trying to reassure Muniz that he would make it, but the crewman's condition continued to deteriorate and he became delirious from blood loss, envisioning that he was attending a carnival with his father. Muniz eventually died from the blood loss, much to his crewmates' despair.
When the Defiant later rescued the team, O'Brien sat in the cargo bay beside Muniz's casket, performing an Irish wake. Worf commented that the ceremony was similar to the Klingon tradition of ak'vah, where the friends of the deceased protect the body from predators while the soul departs from the mortal plane.