1. The deadliest train derailment in US history occurred in Illinois on September 11, 1907. Over 100 people were killed and nearly 200 were injured when a crowded train derailed and collided with several other trains in the small town of Terra Haute.

2. On September 11, 1921, the historic Illinois Theatre in Chicago was destroyed by a massive fire. The theatre had hosted some of the biggest stars of the era, including Charlie Chaplin and Harry Houdini.

3. In 1996, Governor Jim Edgar declared September 11 as "911 Emergency Number Day" in Illinois. The day was meant to recognize the importance of the emergency services and to encourage residents to familiarize themselves with the 911 emergency number system.

4. September 11, 2001, marked the opening day of the 76th General Assembly of the Illinois House of Representatives. In light of the terrorist attacks that day, the legislature suspended its activities and observed a moment of silence in honor of the victims.

5. The Illinois National Guard played a significant role in response to the 9/11 terrorist attacks. Over 2,000 members of the National Guard were mobilized to support the recovery and security efforts in New York city and Washington D.C.