With more than 600 of Chicago’s older residential high-rises not fully protected with fire sprinklers, fires in those buildings can be tragic and devastating. With each passing fire, it becomes further evident that the cost to retrofit fire sprinklers in the buildings is far less than the cost of the fires and resulting aftermath. These fires often present increased probability of injuries and deaths of residents and firefighters, millions of dollars in property loss, and the potential for hundreds of people displaced. The fatal Harper Square Cooperative fire on January 25, 2023, which was the motive for developing the timeline below, is perhaps one of the greatest examples of the tremendous long-term toll of an unsprinklered high-rise fire.