Overview

• The collision occurred just before 7:20 a.m. at milepost 277 on northbound I-55 near the I-294 interchange in Burr Ridge.
• At least one person was taken to a nearby hospital with injuries, though officials have not detailed their condition.
• Illinois State Police closed multiple northbound lanes, causing backups that extended to Cass Avenue during the morning commute.
• Investigators say the crash may have been triggered by a medical emergency experienced by one of the drivers.
• The incident joins a series of serious multi-vehicle crashes on Chicago-area expressways this spring that have tested emergency response protocols.