Following up this article ..Another Fukushima worker suffered cardiopulmonary arrest.
Tepco announced he actually died of cardiac infarct on the day when he was hospitalized.
It was 17:02 1/9/2012.
According to Tepco, he started working at the plant since last May, the total external dose was 6mSv. Total internal dose was 0.01mSv.
Tepco asserts there is no connection between his death and radiation.
About the reason why they concealed his death for 2 days, they state they received the information to tell he died on 1/10 from his family, and received the information from the sub-contract company on 1/11.
(Source)
(Source)
Iori Mochizuki