As the surge of water smashed through the factory wall near Sendai Airport a year ago, Takumi Tanaka held on to an air hose to stop being swept away. Four days later, he was back at the shattered auto parts plant, groping through meter-thick mud studded with uprooted trees.

Tanaka, a 61-year-old manager at Uchida Co., and other employees were searching for molds used to make parts. After finding the dies, they handed them over to another supplier of its biggest customer, Honda Motor Co.

"Without them, Honda's production lines would have ground to a halt," Tanaka said. "Our engineers were in tears."