Chicago

Chicago is the largest city in the U.S. state of Illinois and the Midwestern United States, as well as the third-most populous city in the United States. Chicago itself became a potential spire attack for its population. In October, 1951 President Grace attempted an emergency evacuation of the city. Unfortunately, the evacuation came too late to save the majority of the civilian population as Chimera launched a massive spire attack that infected most of the city within minutes. And all surrounding areas in a 50 mile radius of downtown Chicago were declared gray territory. Sometime during the Chimeran occupation, the Chimeran tower (dubbed the Chicago Tower) under Chicago was excavated.

Within months Chimeran forces were amassing in the city, posing as a threat to the Liberty Defense Perimeter. It is not until SRPA initiated Operation Shadow Strike in April 19, 1952 which Specter Team successfully decimated and contained the Chimeran threat in Chicago by April 22. It is during this operation that SRPA recon Team X-Ray infiltrate the Chicago Tower and learned that its linked to seven other towers; and also important in the tower is Specter's discovery of ancient, advance artifacts known as "Gray Tech", which the team itself is eventually task to find these artifacts.

After the events of Operation Shadow Strike, Specter Team and intelligence analysts at SRPA 3 have reported that the Chimera have constructed a 300-foot-tall enclosure surrounding Wrigley Field which SRPA ignored the enclosure as of unimportance; unfortunately they failed to realized that it is this facility that soon created the Leviathan. Also by the time of the Chimeran invasion most of the city's street and surroundings are submerged in water-infested Furys.

Within a year later, during the Chimeran invasion of America, Echo team and SRPA forces return to Chicago to shut down the Chicago Tower. After defeating Chimeran forces and along with the Leviathan; however, Dr. Malikov and SRPA were unable to shut down the activated tower only to realize that the tower is activated remotely from Iceland.