Sirens blared, trains stopped and mourners bowed their heads Sunday as Japan marked the first anniversary of a twinned disaster that killed about 19,000 and set off a nuclear emergency.

At a theater in Tokyo, Japanese Emperor Akihito, 22 days after heart bypass surgery, stood for a moment of silence at 2:46 p.m. — the precise time when one year ago a 9.0-magnitude earthquake pulsed 80 miles off Japan’s northeastern coast.

In the many small towns devastated by the quake and the resulting tsunami wave — 45 feet high, in some cases — survivors dressed in black and laid flowers in spots where loved ones had died, places that now look like empty construction sites.

And at a baseball stadium in Fukushima, the prefecture (state) where a radiation-spewing nuclear plant forced the evacuation of 90,000 people, anti-nuclear protesters gathered to speak out about an energy source that has turned into one of Japan’s most divisive, and unresolved, issues.

One year later, the mega-disaster — 3/11 as it’s known here — remains a present crisis more than a part of history. It left scores jobless and homeless. It caused at least $200 billion in damage to ports, roads, buildings and other infrastructure, straining an already stagnant economy. Government bickering delayed the passage of reconstruction budgets, and authorities’ much-criticized response to the nuclear emergency at the Fukushima Daiichi facility led to a breakdown in public trust.

The disillusionment with government shows itself in the current debate over nuclear power, where many local communities refuse to allow the restart of reactors on their shorelines. At the moment, just two of Japan’s 54 reactors are in operation, a sharp reversal in a country that before last year depended on nuclear power for one-third of its energy. The reversal comes with a cost, because utility companies have been forced to import fossil fuels to maintain a reliable energy supply, potentially leading to higher bills for consumers and a perpetual trade deficit for the country.

The land immediately around the nuclear plant could be uninhabitable for decades, authorities have said, but even the tsunami-devastated towns untouched by radiation face a tenuous recovery. These fishing towns, even before last year, grappled with problems of shrinking and aging populations. Now these communities, in charge of their own reconstruction plans, find themselves torn between restoring the old way of life and conceiving something different.

More than 300,000 people still live as evacuees, in temporary housing units, hotels or homes of relatives. A recent Asahi Shimbun survey of evacuees found that 40 percent had lost their jobs or sources of income. Separate surveys showed higher levels of depression and insomnia among survivors.

“It’s probably impossible to make life comfortable right now,” said Yoshinori Sato, a worker at the city hall in tsunami-hit Ishinomaki. “Even I suffer from insomnia, though I didn’t lose as much as most people here. I have to take sleeping pills just to fall asleep. Even drinking sake doesn’t help.”

In some ways, Japan’s progress of the past year is obvious, though cosmetic. Towns that were shredded by the tsunami wave, their houses torn to metal and wood, have been cleared of debris and mud. Workers have repaired earthquake-caused chasms in the roads. The bullet train again runs to Sendai, the main city in the tsunami-devastated region.

Some of the more heartening images of reconstruction are displayed at the entrance of the prime minister’s office in central Tokyo. Several months ago, the government urged people to send photographs of “daily happenings” in the disaster zone, and Prime Minister Yoshihiko Noda, in a recent blog entry, mentioned several of the most memorable ones. An infant receiving a massage at a temporary housing facility. Children gorging on Christmas cake.

“Of course, it may be that these have picked out only the brighter side of the disaster areas, and it is not my intention to claim that ‘reconstruction is proceeding smoothly’ based on these alone,” Noda wrote. “At the same time, I would be grateful if, by glimpsing new scenes of people who have set out along the path to reconstruction, even a few more people came to share the wish to continue to be a support in this process.”