RIKUZENTAKATA, Japan — People across Japan prayed and stood in silence Sunday to remember the massive earthquake and tsunami that struck the nation one year ago, killing 19,000 people and unleashing the world's worst nuclear crisis in a quarter century.
In the devastated northeastern coastal town of Rikuzentakata, a siren sounded at 2:46 p.m. — the exact time the magnitude-9.0 quake struck on March 11, 2011 — and a Buddhist priest in a purple robe rang a huge bell at a damaged temple overlooking a barren area where houses once stood.
At the same time in the seaside town of Onagawa, people facing the sea pressed their hands together in silent prayer.
Meanwhile, at a memorial service in Tokyo's National Theater, 78-year-old Emperor Akihito, Empress Michiko and Prime Minister Yoshihiko Noda stood in silence with hundreds of other people dressed in black.
Even in Tokyo's busy shopping district of Shibuya, pedestrians briefly stopped and fell silent before carrying on.
Mr. Noda recalled in a speech that the Japanese people have overcome disasters and difficulties many times in the past, and pledged to rebuild the nation and the area around the tsunami-stricken Fukushima nuclear plant so that the country will be "reborn as an even better place."
"Our predecessors who brought prosperity to Japan have repeatedly risen up from crises, every time becoming stronger," Mr. Noda said. "We will stand by the people from the disaster-hit areas and join hands to achieve the historic task of rebuilding."
The earthquake was the strongest recorded in Japan's history, and set off a tsunami that swelled to more than 65 feet in some spots along the northeastern coast, destroying tens of thousands of homes and bringing widespread destruction.
The tsunami also knocked out the vital cooling systems at the Fukushima Dai-ichi nuclear power plant, causing meltdowns at three reactors and spewing radiation into the air.
Some 100,000 residents who were forced to flee remain in temporary housing or with relatives, and a 12-mile area around the plant is still off-limits.
The emperor voiced concern about the difficulties of decontaminating the land around the plant.
"In order to make the area inhabitable again, we face the difficult problem of removing radiation," he said in a brief address. "We shall not let our memory of the disasters fade, pay attention to disaster prevention and continue our effort to make this land an even safer place to live."
All told, some 325,000 people rendered homeless or evacuated are still in temporary housing. While much of the debris along the tsunami-ravaged coast has been gathered into massive piles, very little rebuilding has begun.
Beyond the massive cleanup, many towns are still finalizing reconstruction plans, some of which involve moving residential areas to higher, safer ground — ambitious, costly projects.
Bureaucratic delays in coordination between the central government and local officials have also slowed rebuilding efforts.
Anti-nuclear protesters at a downtown Tokyo park also held a moment of silence Sunday before marching toward the headquarters of Tokyo Electric Power Co., the operator of the Fukushima nuclear power plant. Public opposition to nuclear power has grown in the wake of the disaster, the worst since Chernobyl in 1986.