The Houston Fire Department said crews responded to the fire at Mustang on the Trail Apartments on Lake Hills Drive at about 3 a.m.
Capt. Sedrick Robinett said one firefighter was taken to the hospital for hypoglycemia and is expected to be OK.
ABC13 spoke with two men, Kevin Rizo and Emilio Rangel, who escaped the flames.
"I came outside, called 911, saw smoke, and got neighbors out. A woman who lived next to my neighbor got the kids out, everybody upstairs got out, from there, the fire took over," Rizo said.
The fire department said about 80 firefighters worked to tame the blaze, and investigators are still working to determine the cause of the fire.
"I was like, 'I'm going to go inside to get my cats, put them in my car, and kind of wait it out. I come back outside. That fire is about ten feet tall, and you can feel the heat, like it was the hottest day of the summer," Rangel said.
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