A contract worker, 60, died after a fall at the facility’s waste disposal building, the operator of Japan's tsunami-wrecked nuclear power plant said.

“The man was carrying equipment at the Fukushima Dai-ichi nuclear plant when he collapsed on Saturday,” said Naoyuki Matsumoto, spokesman of Tokyo Electric Power Co.

No radioactivity at harmful levels was detected in his body and the cause of the death is still unknown, Matsumoto said. “The worker was fully covered with a mask, gloves and radiation protection suit,” he added.

Radioactive-contaminated water that has leaked from the plant’s reactors is stored in the building where the worker died.

The Fukushima Dai-ichi plant still leaks radiation after it was severely damaged by the March 11 earthquake and tsunami.