The Fulshear Simonton Fire Department responded to the Polo Ranch subdivision in the 31600 block of Eldorado Lane after a neighbor called 911 around 9:52 a.m.
The neighbor told ABC13 that she saw smoke coming from the back of the house.
Investigators said there were a total of four victims, with one suffering from severe burns. Two were flown to the hospital by Life Flight in critical condition, and the other two were driven to the hospital with minor injuries.
All victims are expected to survive from their injuries.
The victims' ages have not been released, but a spokesperson for the fire marshal's office said they are all family members.
SkyEye flew over the scene and showed what appeared to be window screens blown off the frame in the home's backyard.
The cause of the fire is still under investigation.
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