The fire broke out around 9:30 a.m. Friday, in the 2500 block of Twin Oaks St., near Pawnee and Hillside.
Firefighters found the 35-year-old man in a back bedroom unresponsive and appeared to have suffered from smoke inhalation. He was pronounced dead at the scene. The 63-year-old man was found in the living room unresponsive and with severe burns. He was transported to a hospital where he later died.
The initial 911 call came from the 63-year-old man who said there was a fire with pets trapped inside the house. When crews arrived, neighbors alerted crews that two people lived at the residence.
Investigators have not yet determined the cause of the fire. The fire was mainly in the living room area and there were multiple space heaters inside the house.
Investigators estimate damage at $30,000.
The men are the third and fourth fire fatalities of the year. There were 8 fire fatalities in 2011.