ST. LOUIS – An investigation is underway after a motorcyclist died in a south St. Louis crash Saturday morning on Interstate 55.

Police responded to I-55 near South Broadway around 1 a.m. after a call from a passerby. When police arrived, the victim was lying on the side of the highway next to the crashed motorcycle.

The victim was rushed to the hospital, but she later died from her injuries. Circumstances leading up to the crash are unknown.

An accident reconstruction team investigated the site of the crash. Additional details are limited at this time. FOX 2 will update as more information becomes available.