OSAKA, Japan - In the face of unseen dangers, the firefighters at Fukushima have the weight of an apprehensive nation's expectations -- and their families' worst fears -- riding on their shoulders.
With radiation leaking from a disaster-hit nuclear plant, the crews have spent days spraying tonnes of water to try to cool overheating fuel rods and prevent a catastrophic meltdown -- potentially risking their own health.
"When I told her that I was going to Fukushima, my wife replied, 'I wish you would be a savior of Japan'," said Yasuo Sato, commander of the Tokyo Fire Department's Hyper Rescue Unit, which sent dozens of firefighters to join the dousing efforts.
Exhausted by his efforts, tears welled up in Sato's eyes as he said he was not sure whether he had lived up to his wife's exhortations.
The Fukushima No. 1 plant on Japan's Pacific coast has suffered a series of explosions and fires since a 9.0-magnitude quake and 10-metre (33-foot) high tsunami on March 11 knocked out its cooling systems.
As a grateful and anxious nation watches the firefighters' efforts, and acclaims the bravery of more than 50 nuclear workers battling away inside the plant, the crews say they are well aware of the danger of radiation.
"We managed to keep within the limit," said Sato.
"As we have ample knowledge of nuclear dangers, we could overcome fear... I believe we have mostly hit the target," the 58-year-old commander said, referring to a containment pool where spent fuel rods should be kept submerged.
The radiation reading outside the No. 3 reactor unit declined after the operation by the firemen, clad in protective gear. They used a fire truck with a tower able to shoot out a jet of water from a height of 22 metres.
A 350-metre-long hose carried seawater from the plant's quay to the truck through heaps of debris from the No. 3 reactor's roof and walls, which have been shattered by hydrogen explosions.
"The morale of our unit members was very high," said another team leader, Toyohiko Tomioka. But he choked with emotion when asked what was the toughest part of their job.
"You know it's our families we have left behind. I've really felt sorry for them. I want to apologise to them here and now," he said.
The firefighters described their efforts as a battle against an unseen foe in the form of radiation.
"It was a fight against an invisible enemy," said Yukio Takayama, the 54-year-old leader of a Tokyo Fire Department elite squad that returned late Saturday from the plant 250 kilometres (155 miles) northeast of the capital.
"It was quite tough to complete our activity and bring our unit members back to safety in a short period of time," he told a news conference in Tokyo after returning from the power station.
Military helicopters and fire trucks have also been taking part in the operation, as well as several water pumps provided by the US armed forces.
Japan's nuclear safety agency on Friday raised the Fukushima crisis level from four to five on the international scale of gravity for atomic accidents.
The move puts Fukushima on the same level as the 1979 accident at Three Mile Island in Pennsylvania, behind the maximum category-seven Chernobyl disaster of 1986.
Plant operator TEPCO said Sunday that six of its workers at the quake-stricken facility had been exposed to high levels of radiation but were in good health and still working to restore power to the cooling systems.