Tony Diaz was the final member of the firefighting trio who touched the Chitauri helmet, and was visibly ill when the agents caught up with him at the Wrigley, Pennsylvania firehouse. On a quiet shift, three of the firefighters had decided to polish their trophy from the Battle of New York, a souvenir of their efforts as volunteers after the conflict. It, however, housed a dormant virus, activated by the friction of rubbing, and infecting all three men. An electrostatic charge built up inside the sufferer, eventually manifesting as a violent, and fatal, discharge. Tony was beyond the team's help, but Agent Coulson insisted on staying with him and trying to keep him company longer than was safe. Coulson's own 'near death' experience drove him to give Tony every chance to state any last requests. He eventually sent Coulson away, and was lost in a flash clearly visible from outside the building. He did not infect Coulson, unlike Jemma Simmons's postmortem interaction with Adam Cross.