The quake hit at 14:46 local time (05:46 GMT) and this is how the disaster unfolded Japan's most powerful earthquake since records began has struck the north-east coast, triggering a massive tsunami. Cars, ships and buildings were swept away by a wall of water after the 8.9-magnitude tremor, which struck about 400km (250 miles) north-east of Tokyo. A state of emergency has been declared at a nucle