Once the rain stopped, the temperature quickly soared to 100+ degrees. This quickly dried the surface in many places (though the really deep spots, where the water was six feet or more deep, would take a while to show any signs of diminishing). A few eager folks thought this signaled the time to depart. However, the dry surface hid a deep layer of mud, and so all early attempts ended in vehicles needing to be towed.
The image below is of tire tracks from one of these ill-fated escape attempts.