The authors have spoken to several workers at the plant who recite the same story: Serious damage to piping and at least one of the reactors before the tsunami hit. All have requested anonymity because they are still working at the plant or are connected with TEPCO. One worker, a maintenance engineer in his late twenties who was at the Fukushima complex on March 11, recalls hissing and leaking pipes. “I personally saw pipes that came apart and I assume that there were many more that had been broken throughout the plant. There’s no doubt that the earthquake did a lot of damage inside the plant," he said. "There were definitely leaking pipes, but we don’t know which pipes – that has to be investigated. I also saw that part of the wall of the turbine building for Unit 1 had come away. That crack might have affected the reactor.”

The reactor walls of the reactor are quite fragile, he notes. “If the walls are too rigid, they can crack under the slightest pressure from inside so they have to be breakable because if the pressure is kept inside and there is a buildup of pressure, it can damage the equipment inside the walls so it needs to be allowed to escape. It’s designed to give during a crisis, if not it could be worse – that might be shocking to others, but to us it’s common sense.”

A second worker, a technician in his late 30s, who was also on site at the time of the earthquake, narrated what happened. “It felt like the earthquake hit in two waves, the first impact was so intense you could see the building shaking, the pipes buckling, and within minutes, I saw pipes bursting. Some fell off the wall. Others snapped. I was pretty sure that some of the oxygen tanks stored on site had exploded but I didn’t see for myself. Someone yelled that we all needed to evacuate and I was good with that. But I was severely alarmed because as I was leaving I was told and I could see that several pipes had cracked open, including what I believe were cold water supply pipes. That would mean that coolant couldn’t get to the reactor core. If you can’t sufficiently get the coolant to the core, it melts down. You don’t have to have to be a nuclear scientist to figure that out.”

As he was heading to his car, he could see the walls of the reactor one building itself had already started to collapse. “There were holes in them. In the first few minutes, no one was thinking about a tsunami. We were thinking about survival.”

A third worker was coming into work late when the earthquake hit. “I was in a building nearby when the earthquake shook. After the second shockwave hit, I heard a loud explosion that was almost deafening. I looked out the window and I could see white smoke coming from reactor one. I thought to myself, ‘this is the end.’”

When the worker got to the office five to 15 minutes later the supervisor ordered them all to evacuate, explaining, “there’s been an explosion of some gas tanks in reactor one, probably the oxygen tanks. In addition to this there has been some structural damage, pipes have burst, meltdown is possible. Please take shelter immediately.” (It should be noted that there have been several explosions at Daiichi even after the March 11 earthquake, one of which TEPCO stated, “was probably due to a gas tank left behind in the debris”.)