The fire broke in the 10800 block of Donna Drive, just outside the West Sam Houston Tollway in the Cy-Fair area, around 2 a.m. Friday.
The grandmother who was killed lived inside the home alone and had limited mobility, fire officials said. A dog was also killed in the fire.
A neighbor called 911 after they saw the flames and smoke early Friday morning.
The Cy-Fair Fire Department responded to the scene, along with the Harris County Sheriff's Office.
Fire officials worked quickly to put the fire out, and when they forced entry into the home, they found the body of the 83-year-old woman.
Officials said the victim's son runs his pest control business out of the house. There are people at the home during the day, but the grandmother stays there alone at night.
The fire reportedly started in the residential area of the home. The cause is unclear, but the Harris County Fire Marshal's Office is investigating.
"There is extensive damage in the house. So we are still going through the whole house to clear it out and help the fire marshal's office make that determination," Jeremy Wenger with the Cy-Fair Fire Department said. "Mainly center of the house, as well as the bedrooms on the south side of the house, are pretty well-engulfed in fire. The north side of the house is a business, but that didn't seem involved in the fire."
Firefighters said they did not hear fire alarms going off when they arrived at the scene. It's unclear if there were fire alarms inside the home, or if they were in working order.
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