On Sunday, July 13, 1980, around 500 children from 11 marching bands gathered at the Hollinwell Showground near Kirkby-in-Ashfield, Nottinghamshire, for a Junior Brass and Marching Band competition. At about 10:30 am, band members began to collapse. Children began "[falling] down like nine pins," according to one witness. Symptoms included fainting, vomiting, sore eyes and throats, and dizziness. One girl said, "My legs and arms felt as if they had no bones in them and I had a bad headache."
Around 300 people were affected — children, adults, and babies — and 259 were taken to four nearby hospitals. The Hollinwell incident has never been conclusively explained. Ashfield District Council investigated contaminated water, food poisoning, radio waves, and crop spraying. A 2003 BBC investigation revealed that the pesticide tridemorph — later banned by the British government and described by the WHO as "moderately hazardous" — had been used in nearby fields. But those findings came 20 years after the event and contradicted the official inquiry, which blamed mass hysteria.
People present at the event rejected the hysteria explanation, insisting their symptoms were real. A 2022 BBC podcast offered a new theory: different cleaning products used in a temporary toilet block may have combined to create chlorine gas. The official report into the incident "was produced but could not be traced afterwards."
