In the course of investigating the odor, the crews forced entry into a first floor apartment to conduct a search for occupants and a source of the odor. They made access to the rear of the apartment, locating a bathroom where they observed a hand written sign on the door stating “Danger! Requires hazamat [sic] suit!!” The crews made entry into the bathroom and removed a 30 year old male from the bathroom to hallway. Upon assessment, the patient was determined to be deceased. The crew exited the apartment and requested the response of the Hazardous Materials Team while completing the evacuation of the apartment building.