Nearly a million homes suffered blackouts in Japan's north east after a strong aftershock that killed two people and piled more misery on a region buried under the rubble of last month's devastating tsunami.
The north-eastern coast was still reeling from the destruction wrought by a 9.0-magnitude earthquake on March 11, with tens of thousands of households without power or water. The new 7.1 tremor on Thursday threw even more areas into disarray and sent communities that had made some gains back to square one.
Petrol was scarce again, and long lines formed at stations. Stores that had recently restocked their shelves sold out of basics and were forced to ration purchases again.
The latest quake did far less damage, generated no tsunami and largely spared the region's nuclear plants. Some slightly radioactive water spilled at one plant, but the tsunami-crippled Fukushima Dai-ichi complex reported no new problems.
The latest tremor - the strongest since the day of the tsunami - cut power to more homes, though it was quickly restored to many, said Souta Nozu, a spokesman for Tohoku Electric Power, which serves northern Japan. That includes homes in prefectures in Japan's north west that were spared in the first quake.
Six conventional power plants in the area were knocked out, though three have since come back online and the others should be up again within hours, Mr Nozu said. But with power lines throughout the area damaged, it was not clear whether normal operations would be restored.
Several nuclear power plants briefly switched to diesel generators but were reconnected to the grid by Friday afternoon. One plant north of Sendai briefly lost the ability to cool its spent fuel pools, but quickly got it back.
At a plant in Onagawa, some radioactive water splashed out of the pools but did not leave a containment building, Tohoku Electric said. Such splash-out is "not unusual, although it is preferable that it doesn't happen", according to Japanese nuclear safety agency official Tomoho Yamada. "Closer inspection could find more problems," said agency spokesman Hidehiko Nishiyama, but no radiation was released into the environment at Onagawa.
The plant began leaking oil into the ocean in the first earthquake, and the flow escaped a containment boom in Thursday's tremor but was contained again by Friday, coast guard spokesman Hideaki Takase said.
Thursday's quake prompted a tsunami warning of its own, but it was later cancelled. Three people were killed, national fire and disaster agency spokesman Junichi Sawada said. A 79-year-old man died of shock and a woman in her 60s was killed when power was cut to her oxygen tank. The third death was an 85-year-old man, but the circumstances were unclear.