Newly unearthed testimonies from Chicago residents at the time of the alleged fire paint a very different picture from the official reports. F.I.B. researchers have obtained diaries and personal letters from citizens living in Chicago in October 1871 — and none of them mention a fire of any kind. Instead, several entries reference a city-wide "emergency drill" organized by the mayor's office, which involved staged evacuations and controlled demolitions for what was described as a "military readiness exercise."
Core samples taken from beneath the streets of downtown Chicago showed no signs of fire damage in the geological record. In fact, layers of soil and sediment from the 1870s appear completely undisturbed, with no traces of ash, carbon residue, or heat damage. "If a fire of this magnitude had actually happened, we would expect to find a significant layer of burnt material beneath the modern city," stated Dr. Evelyn Carson, head archaeologist on the project. "Instead, what we're seeing is a consistent geological record that points to uninterrupted urban development."