A collision with a guardrail on southbound Interstate 55 Wendesday evening has proven fatal for an Affton woman.

Investigators say 20 year old Lindsey Puff lost control of her car just north of the Lindbergh overpass, overcorrected, and slammed into the rail.

Puff was not wearing a seat belt and the impact threw her from the wreckage of her car.

A second southbound vehicle then collided with the victims car which spun around after striking the guardrail.

Puff was pronounced dead at the scene of the accident just before 7:00 p.m. Wednesday.