Dome Day occurred on 21 October in the Year of the Dome, when an invisible barrier sealed off the town of Chester's Mill, Maine from the rest of the world. The "Dome," as the United States Army referred to it, appeared at 11:44 AM, and occurred at a magnitude of 2.1 on the Richter scale. Research into determining a way to breach the Dome became known within the military as "the Dome Project."
Numerous people died as a result of the Dome's sudden appearance, including Chuck Thompson, Claudette Sanders, Myra Evans, Robert Roux, Nora Robichaud, Billy Debec, Wanda Debec and Howard Perkins. Angie McCain and Dodee Sanders also died on Dome Day, though their deaths were not directly related to the appearance of the Dome.