The Atlanticwire.com has the long story here, including testimony from three different workers:
“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. 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.”
“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.” (first worker)
“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.”
“There were holes in them [the walls of Unit 1]. In the first few minutes, no one was thinking about a tsunami. We were thinking about survival.” (worker two)
“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.’” (worker three)
Worker three, quoting a supervisor: “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's a little odd that the story concludes with this statement:
[S]haking experienced at the plant during the quake was within it’s [sic] approved design specifications.
Three readings from TEPCO's own report of the seismic data, updated June 16, 2011, contradict this statement for Units 2, 3, and 5, and Unit 1 got very close to not just its E-W limit, but also its N-S, which would cohere with its geographic position at the plant, bearing the brunt of the forces from the north, and sharing in the record-setting forces from the east:
Workers fleeing west before the tsunami hit were reported here to have heard a radiation alarm sounding at a point 1.5 km distant from reactor Unit 1.
