Over 800 patients were victims of radiation overdoses during radiotherapy sessions in a hospital during 2004 and 2005. The overexposure to X-rays caused the deaths of 4 patients, and 20 others were very seriously irradiated. According to a report from the nuclear safety authority, these overexposures stemmed from: a computer data entry error in the dosimetry software used during treatment preparation, lack of personnel training in the use of this software, and a poor software user interface. No traceability of operations could be performed. Machine operators were given no user’s guide in French adapted to their day-to-day use. 14 individuals filed a suit following the accident: 4 for involuntary manslaughter and 10 for involuntary injuries.