The man heard a window break overnight and thought it was a burglary, HPD said.
The Willowfork Fire Department said no one was home at the time of the fire, but the flames consumed much of the attic, and three firefighters had to be treated for heat exhaustion.
Fire officials told ABC13 the fire was in a detached residence at the back of the home where the 74-year-old woman lives. The cause of the fire is unknown.
Fire department officials said emergency crews responded to a house fire in Houston's east side and rushed a man to the hospital due to multiple burns.
A Galveston County jury convicted Courtney Thompson Jr. of intentionally setting the 2024 house fire that killed Renita Hawthorne as retaliation for her son owing drug debt.
HFD went to an apartment fire that was caused by food left on the stove and a single-story house fire, where a firefighter fell through the roof, within hours of each other.