The trash truck making its rounds backed up and ran over the 76-year-old man who was pushing a cart on his way to buy water.
"The driver did state that he heard a noise," said Officer Colin Quayle of the California Highway Patrol. "However, he continued backing and didn't realize what he had hit until he saw the body of the gentleman."
Investigators said the trash truck used an alley to get around and was backing up to get back to the homes he missed.
The truck is equipped with a camera facing toward the rear, but the driver told investigators he never saw the victim.
"He was a very humble person," said the victim's niece, Anna Ruiz. "We all loved him. All the neighbors loved him."