In the tense days after a powerful earthquake and tsunami crippled the Fukushima Daiichi power plant in Japan on March 11, 2011, staff at the U.S. Nuclear Regulatory Commission made a concerted effort to play down the risk of earthquakes and tsunamis to America's aging nuclear plants, according to thousands of internal emails reviewed by NBC News. The emails, obtained via the Freedom of Information Act, show that the campaign to reassure the public about America's nuclear industry came as the agency's own experts were questioning U.S. safety standards and scrambling to determine whether new rules were needed to ensure that the meltdown occurring at the Japanese plant could not occur here. At the end of that long first weekend of the crisis three years ago, NRC Public Affairs Director Eliot Brenner thanked his staff for sticking to the talking points that the team had been distributing to senior officials and the public. While we know more than these say," Brenner wrote, "we're sticking to this story for now." There are numerous examples in the emails of apparent misdirection or concealment in the initial weeks after the Japanese plant was devastated: When asked to help reporters explain what would happen during the worst-case scenario -- a nuclear meltdown -- the agency declined to address the questions. The emails pull back the curtain on the agency's efforts to protect the industry it is supposed to regulate. The NRC officials didn't lie, but they didn't always tell the whole truth either. When someone asked about a topic that might reflect negatively on the industry, they changed the subject.