Just after 10 a.m. Wednesday, firefighters arrived to find a North Street mobile home engulfed in flames.
A woman suffering from burns screamed her child was inside. A neighbor tried to help, but the heat and smoke kept him from entering.
Daleville Department of Public Safety officer Jason Haynes and volunteer firefighter Patrick Sullen managed to get in. Four-year-old Mason Hood was face down in a bedroom and not breathing.
Mason was airlifted from Medical Center Enterprise to the University of Alabama-Birmingham Children's Burn Center. He is listed in critical, but stable condition.
Officials said the fire appears to have started in the living room of the Daleville mobile home.
The State Fire Marshall's Office has been called in to determine a cause.