UPDATE at 8:30 a.m. Sunday. All lanes of Interstate I-55 and subsequent ramps have reopened.
Around 3:30 p.m. Saturday, officers from the Affton Southwest Precinct and South County Precinct responded to a train derailment on train tracks between Butler Hill Road and Lindbergh Boulevard over Interstate 55.
PHOTOS: Train derailment shuts down I-55
No injuries were reported in the incident.
As more information becomes available, this story will be updated.