Ciudad Juárez cobalt-60 contamination incident

A radioactive contamination incident occurred in 1984 in Ciudad Juárez, Mexico, originating from a radiation therapy unit purchased by a private medical company and subsequently dismantled for lack of personnel to operate it. The radioactive material, cobalt-60, ended up in a junkyard, where it was sold to foundries that inadvertently melted it with other metals and produced about 6,000 tons of contaminated rebar.

Source: Wikipedia — Ciudad Juárez cobalt-60 contamination incident (CC BY-SA 4.0)