Dudley Hatcher, nicknamed "Dirty Gertie", was a student at Coal Hill School. In March–April 1963, he was in Year Five, one year ahead of Susan Foreman.
Dudley was known to have a strong and somewhat perverse interest in the opposite sex. During the unseasonable cold of March 1963, a Coal Hill student carved the warning "Girls Beware — Dirty Gertie at Large!" into the ice which grew around the school buildings.
On 1 April 1963, Dudley was given detention for looking up girls' skirts. He and the other students on detention that afternoon (Susan Foreman, Gillian Roberts, Joe Gibson and three other boys) were tasked with removing the ice from the school buildings. Mr Okehurst supervised the detention, and ordered Susan and Gillian to go up ladders with blowtorches, to remove the ice from the gutters. He insisted that Dudley should not hold the ladder. Unfortunately, the ice was animated by the Cold. After Susan and Gillian attempted to melt it, it rose up and killed Dudley, Joe, the other boys, and Mr Okehurst. Only Susan and Gillian escaped. (PROSE: Time and Relative)