It happened in the 700 block of South Fairview Street, just north of McFadden.
Officers initially received a call about someone in the middle of the street. When they arrived, the person was found dead.
Drivers believed to be good Samaritans reportedly stayed on the scene until help arrived.
Information on a suspect or a suspect vehicle wasn't immediately available. Video captured several officers analyzing debris left on the scene Friday morning amid heavy fog.
It's unclear if weather played a role in the crash. The incident remains under investigation.
Anyone with information is urged to contact authorities.