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(CNN) – Dozens of American sailors and Marines who served in the Navy's mission are now reporting a series of serious health issues following their deployment to Japan to aid victims of the tsunami.
Now, they're suing Tokyo Electric Power Company, or TEPCO, saying the company was anything but forthcoming with the threat the citizens of Japan – and the American service members trying to help them – truly faced.
The March 2011 earthquake off the coast of Japan triggered a deadly tsunami, killing scores of people. Waves swamped TEPCO's Fukushima Daiichi Nuclear Power Plant. Huge explosions followed, and ultimately meltdowns of three of the six nuclear reactors, spewing radioactive material into the atmosphere.
Into this unknown sailed the USS Ronald Reagan, a nuclear-powered super carrier with more than 5,000 sailors and Marines on board. The carrier was a key part of the Navy's Operation Tomodachi, the Japanese word for friends.
But now, three years later, more than 70 sailors and Marines from the mission have filed a billion-dollar lawsuit against TEPCO, alleging the company withheld information that led to radiation exposure causing illness, and even cancer.
Medical experts are skeptical of a connection, but the cases are heart-breaking
Lindsay Cooper and Kim Gieseking both served on the Reagan, and said since they got back they've faced debilitating thyroid issues.
Thomas McCants was on the USS Germantown in July 2011 when it responded to Japan. When he returned, he was diagnosed with leukemia, he told CNN.
And then there's Navy Officer Steve Simmons, who served on the Reagan. Before he set sail he was an avid hiker in the mountains of Hawaii, and said his health was "great" in the months leading up to deployment.
"The summer of 2010 ... when we pulled into Hawaii, I was actually out, doing trail runs. A couple days later I went and hiked Diamond Head. The following day from Diamond Head, I actually went and hiked Stairway to Heaven," Simmons told CNN.
But Simmons says something happened to him off the coast of Japan. A year after returning to the U.S., he lost all control of his legs.
Doctors tell Simmons they have no idea what is wrong with him. "The don't know," says Simmons.
Two moments during his deployment stick out to Simmons. At one point, the ship stopped taking in water from the sea and purifying it because of contaminants, But Simmons says he had already had some of it to drink that day.
"The water feeds everything – the showers, the water faucets, the soda machines," said Simmons. Securing the water because of contaminants "was a first for everybody on board."
The Reagan also sailed through the post meltdown nuclear plume for hours leading to a thorough decontamination. The ship locked down the ventilation system, Simmons said.
That account fits with prior reporting by CNN's Bill Weir who tried to get on the ship for a story, and was waived off by commanders citing radiation concerns.
The Navy declined CNN's interview request because of the pending litigation, but in a statement, a spokesman said: "There is no indication that any U.S. personnel supporting Operation Tomodachi experienced radiation exposure at levels associated with the occurrence of long-term health effects."
The Navy acknowledged the ship sailed through the nuclear plume, but disputed a key point in the lawsuit.
The complaint alleges the Reagan was operating two miles off the coast. The Navy told CNN repeatedly the Reagan "was operating approximately 100 miles out to sea."
There was great concern from the Navy. CNN's Martin Savidge was on board the Reagan during part of its month long deployment. His team, like the sailors, went through constant radiation testing and decontamination after being on deck.
"There was some misleading information that was given, and not from the stand point of the Navy or (the Department of Defense)," said Simmons. "That information that we were using to make decisions was all being fed from Japan and TEPCO."
In response to CNN's questions about the suit, the power company issued a statement thanking the U.S. for its aid, but adding: "We withhold any comments on this lawsuit, and we will take appropriate measures in accordance with the judicial procedures in the United States."
TEPCO has until April to respond in court.
There is no question Simmons's health has radically deteriorated since his time on the Reagan. But why?
"There was probably some exposure to radiation on the USS Ronald Reagan. But saying "some" manifests to many people that any exposure to radiation is going to be dangerous. That is actually not the case," said Cham Dallas, director of the Institute for Disaster Management at the University of Georgia, a respected radiation expert who has led seven expeditions to Fukushima.
Dallas said the Navy's calculations suggest the radiation exposure of the sailors and Marines was about the same as taking a transatlantic flight – not very much. He says health effects from radiation, like cancer, take years or even decades to show up.
For Dallas and other experts CNN consulted, these illnesses are too soon to be from Fukushima.
"You have an exposure to radiation, and then there's a pause, there's a certain period of time, before the health effects start to come," said Dallas.
So what is the reason dozens of sailors and Marines exposed to radiation are having these health problems? Does the Navy, and do these experts know everything that went on at Fukishima?
Getting to the truth cannot come quickly enough for Steve Simmons, and his wife Summer. Like the 78 other plaintiffs, they hope time will bring compensation from TEPCO, or at the very least more information.
Until then, the Simmons family is trying to cope as best they can, going so far as to re-shoot the memories of their wedding day, so the pictures are no longer a reminder of what once was.
"We retook our wedding pictures to include the chair. Because we wanted to be able to look forward,, instead of looking back. And we wanted our wedding photos to be what we are," Summer Simmons said.
Steve Simmons is in the process of being honorably discharged from the Navy for medical reasons. He continues to wait for a diagnosis so he and his family can sort out what their next steps should be.
The budget bill Congress passed last month demands that the Pentagon provide congress a full accounting for the health of all those who served on the USS Ronald Reagan.
Steve and Summer Simmons asked CNN to mention that their conversion van was provided by Help Our Military Heroes, a charity that provides vans for wounded warriors. Find out more here.