It happened around 1:30 a.m. at the Providence Champions apartments on FM-1960 near Champions Forest Drive.
It began when a car caught fire, and the flames spread to the apartment units, according to authorities on the scene.
Deputies with the Harris County Sheriff's Office were assisting in alerting residents to the fire and getting them to safety when two of them were overcome with smoke, authorities said. They were taken to a hospital for smoke inhalation. A firefighter on the scene also injured his knee during the response. Authorities on the scene told ABC13 that all were alert and were expected to make a full recovery.
"These guys were going door-to-door knocking and making sure all the residents got out," said Harris County Fire Marshal's Office spokesperson Rachel Neutzler. "So they're true heroes tonight and saved countless lives."
WATCH: Video shows firefighters and deputies working to put out the fire and get people to safety
A female resident jumped from the second floor and was hurt, but she was not transported for injuries, authorities said.
It wasn't yet clear what caused the car to catch fire.
At least 20 apartment units were damaged by the fire, but that number could grow as investigators comb through the mess.
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