Deputies say the crash happened at around 2:14 p.m. in the 16400 block of Woodrow Street.
The 2-year-old girl was taken to the hospital with CPR in progress and was pronounced dead after arriving.
Eric Albers with the Harris County Sheriff's Office Vehicular Crimes Division said the child's father found her lying injured outside their home and flagged down a neighbor who was pulling in to their shared driveway.
Initially, HCSO believed the neighbor in a red SUV hit and killed the girl, but throughout the course of their investigation, deputies determined that was not the case.
It is unknown who struck the girl.
The family lives on a property that contains three or four townhomes, according to deputies. All vehicles that belong at the homes have been accounted for.
Albers said it is their belief that the person who hit the child fled the scene.
Anyone with information is asked to call the sheriff's office at 713-221-6000.
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