The catastrophe at the Chernobyl nuclear plant in the Ukrainian SSR was caused by an irresponsible safety test on a reactor design that is normally safe, some operators lacking an even basic understanding of the reactor's processes and authoritarian Soviet bureaucracy, valuing party loyalty over competence, that kept promoting incompetent personnel and choosing cheapness over safety. The consequent release of fallout resulted in the evacuation and resettlement of over 336,000 people leaving a massive desolate Zone of alienation containing extensive still-standing abandoned urban development.