On September 13, 1987, a Césio-137 capsule, removed from abandoned medical equipment in Goiânia, Brazil, triggered the largest radiological accident outside a nuclear facility.
Four people died, 249 were identified as contaminated, and over 112,000 required monitoring. The accident was only discovered more than two weeks after the capsule was opened, when symptoms began to appear and were linked to the radioactive substance.
