Grosse-Île: The Quarantine Station That Became a Secret Bioweapons Base

Grosse-Île sits in the Saint Lawrence River, about 50 kilometers from Quebec City. From the 19th century, immigrant ships had to stop there for disease screening. Passengers with fevers, coughs, or signs of infection were held back. Even the healthy could wait days before being allowed to proceed. The island existed to stop disease from entering Canada.

The quarantine station stopped receiving immigrants in 1937. Five years later, the Canadian Department of National Defence took over the same land for biological warfare research. Buildings that once held the sick were now ringed by military rules, laboratories, and personnel with special clearances. A place designed to keep pathogens out of the mainland was turned into a place that made and tested agents capable of paralyzing whole cities.