Police tell ABC 4 Utah it happened at 4005 South and 5600 West.
Officers say a woman was crossing the street with a stroller in an area where there was no crosswalk. She made it across the southbound traffic, but then the stroller was hit by a car going northbound. The two-year-old was taken to Primary Children's Medical center in extremely critical condition, but died early Tuesday.
The car didn't stop after the accident. Police are looking for the car and its driver. The car is described as a silver, gray or white sports car with a fin on the back. Police believe it will have front end damage because of the accident.
If you know anything about the accident, call West Valley Police.