After the secondary emergency pumps (run by back-up electrical batteries) ran out, one day after the tsunami on 12 March, the water pumps stopped and the reactors began to overheat.
Setelah pompa darurat sekunder (dijalankan oleh baterai listrik cadangan) habis, suatu hari setelah tsunami, 12 Maret, pompa air berhenti dan reaktor mulai terlalu panas.