The Fukushima District Court is due to rule next month on a claim that Tokyo Electric Power Co. is responsible for a woman's suicide, in a landmark case that could force the utility to publicly admit culpability for deaths related to the Fukushima nuclear disaster.

In July 2011, nearly four months after the massive earthquake and tsunami that triggered a series of catastrophic failures at the Fukushima No. 1 nuclear plant, Hamako Watanabe returned to her still-radioactive hilltop home, doused herself in kerosene and set herself on fire.

She left no suicide note but her husband, Mikio, says plant operator Tepco is directly responsible.