The former chief of Fukushima No. 1 nuclear plant died on Tuesday of esophagus cancer, at the age of 58.
Masao Yoshida stayed at his post to try and fix the three runaway reactors at the crippled nuclear plant after the quake and tsunami in 2011.
Yoshida was at the power station on March 11, 2011, when high waves flooded the cooling systems and sparked the meltdowns that released trails of radiation, Japan Times reports.
According to the report, he led the subsequent effort to get the crippled nuclear plant under control, as workers battled frequent aftershocks to try to prevent the disaster from worsening.
A Tepco spokesman announced that Yoshida died of esophagus cancer at a Tokyo hospital, adding that his cancer was not related to radiation exposure.
Yoshida left the plant soon after being suddenly hospitalized in late November 2011. He was still employed by the company at the time of his death, the report added.