By that evening, Jaczko's subordinates were already starting to hedge their assessments about the pool when the chairman joined another conference call. The U.S. staffers in Tokyo had heard from Japanese investigators that even though the exterior wall protecting the pool appeared to be demolished, an interior wall was evidently intact; the Japanese offered other evidence as well.
Chuck Casto, the Tokyo-based team leader, related those points to Jaczko, saying he still wasn't convinced even after seeing a video of what the Japanese claimed was water in the pool. To Casto it was "really inconclusive." But he acknowledged that the video, taken from a helicopter 14 hours earlier, showed steam emissions.
"So at this point, you no longer believe that the pool is dry? Is that what I'm hearing?" Jaczko asked, according to the transcript.
"I would say, as of 5 o'clock yesterday, the pool had some water in it," Casto replied.
"OK. Now, I've publicly said the pool is dry," Jaczko said, which Casto knew. "Do you think that's inaccurate?"
"It's so inconclusive, we can't really tell, either way. I mean ... " Casto replied.
"Well, so it's inaccurate for me to say it's dry?" Jaczko said. "Is that what you're saying? It's OK if that's the case; just tell me."
"I would say it's probably inaccurate to say it's dry," Casto replied. "It appears today, with the video, that they had some water in it at 5 o'clock yesterday or it wouldn't be steaming."
Although this information wouldn't change the evacuation zone expansion, it "speak[s] to my credibility—that's the problem," Jaczko said.
Instead of promptly acknowledging that his public comment evidently went too far, Jaczko stuck by it in the days that followed. Although he sometimes used phrases like "I hope our information is inaccurate," his agency did not publicly admit until June 15, 2011, three months later, that the Japanese assessment had been right all along.
In an interview, Jaczko defended the stance he took as based on information he and his staff firmly believed at the time. "We were looking at data and gathering information and trying to assess: Is the pool dry or not? Our conclusion was: The pool was dry," he said. In fairness to him, the transcripts of calls after the one recounted above show that some staffers overcame their doubts and grew increasingly convinced of the pool's dryness; at one point Casto said he would “stake my career on it." But the transcripts are also replete with uncertainty, such as this March 19, 2011, comment from another staffer: "We can hold a poll around the room of what people think is the actual conditions in that pool, and I think—there's six people, you'll get seven answers."
Whatever damage was done on March 16, 2011, it is worth reflecting on a memo that circulated within the commission staff shortly before Casto and the other experts flew to Tokyo.
"Public statements we make going forward will have enormous credibility; extreme caution will be necessary," said the memo, written by Margaret Doane of the commission's international staff. "The Japanese are now in their fourth day of responding to these emergencies and will remain the best informed about the current technical, legal, cultural, and regulatory issues. ... It will be essential to help the Japanese maintain trust in their leaders. ... Any inconsistencies or statements that undermine Japanese authority or expertise will have lasting effects as it could hamper current emergency efforts and their future ability to respond to these issues, long after international assistance recedes. Any interactions with the Japanese, other nations, or public communications should take this into consideration."
A Japanese-language version of this article was previously published in Newsweek Japan.