Springfield, IL (CAPITOL CITY NOW) – We now officially know what happened to cause a huge traffic backup on Interstate 55 in Springfield late Tuesday morning, and the end result was a self-inflicted gunshot wound.

Illinois State Police said Wednesday it started with a police chase, beginning in Tazewell County, with a man wanted for a Criminal Sexual Assault by Washington, IL Police.  Troopers say it ended on Interstate 55 southbound near the Sangamon Avenue exit, when troopers deployed stop sticks and the vehicle became disabled.

Officers approached the vehicle, troopers say, and discovered a man with “an apparent self-inflicted gunshot wound.”  That man was taken to a Springfield hospital following treatment at the scene, where he later died.

Illinois State Police describe it as an ongoing investigation, and that no further information will be released.  Traffic on southbound I-55 was backed up hours due to the investigation.