Denver Health officials identified the victim as Thomas Hardy. He remains in critical condition, the hospital says.
Fire dispatchers received a call just after 1:47 a.m. of smoke in the area of Downing Street and Speer Boulevard. Crews were driving up and down streets and alleys when they spotted smoke and a faint glow coming from a door in the back of a house in the 300 block of Downing Street.
Denver Fire Department Lieutenant Phil Champagne says as firefighters began to attack the fire, they searched the building and found an unresponsive Hardy in a rear bedroom of the home.
They brought him to safety and began CPR, but Hardy was still unresponsive when he was taken from the scene by ambulance to an area hospital.
Firefighters also found two dogs that died in the fire.
Champagne says firefighters were able to put the fire out about 15 minutes after they arrived on scene, but there is major damage to the interior of the home.
Denver Fire Department investigators are still determining the cause of the fire.
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