Possibly the worst contamination incident since Chernobyl was a little-known event that began in September 1987, when two thieves broke into a disused clinic in Goiana, Brazil. They stole parts from an old machine and sold them to a scrap dealer, who noticed the metal gave off a strange blue glow in the dark. He broke the machinery open and handed out its blue crystals to members of his family. Within days they were falling critically ill and panic was spreading through the city. The crystals were caesium-137, a deadly radioactive substance, and the machine was an X-ray unit.