Therac-25
The Therac-25 was a computer-controlled radiation therapy machine produced by Atomic Energy of Canada Limited (AECL) in 1982 after the Therac-6 (neptune) and Therac-20 units (the earlier units had been produced in partnership with Compagnie générale de radiologie (CGR) of France). The Therac-25 was involved in at least six incident overdoses of radiation between 1985 and 1987, leading to patient death, and contending what was, at that time, described as "the worst series of radiation accidents in the 35-year history of medical accelerators".