HOUSTON -- A father unknowingly hit and killed his 2-year-old daughter at their northwest Houston home on Friday, police told KPRC Local 2.

Investigators said Ruth Santo unlocked the front door, walked outside and in front of her father's Ford pickup truck as he was leaving for work shortly before 9 a.m. in the 2100 block of Delery.

The father did not realize his daughter was outside or that he had hit her in the street until his wife called him about the accident, police said.

The mother said she was inside with Ruth's twin and brother, and did not realize the toddler was outside.

Thelma Santo said she was in the bathroom at the time of the accident.

"I always take care of them, even if I take them to the restroom with me. When something's going to happen, something's going to happen. I was always taking care of them and I was telling myself, 'Why didn't I look for her?'" Santo said.

Ruth died at the scene.

Houston police are investigating.

More Information:

Kids and Cars: Driveway Safety