SENDAI, Japan — Japan reeled from a rapidly unfolding disaster of epic scale on Sunday, pummeled by the death toll, destruction and homelessness caused by the earthquake and tsunami and new hazards from damaged nuclear reactors that were leaking radiation. The prime minister called it Japan’s worst crisis since World War II.
Japan’s $5 trillion economy, the third largest in the world, was threatened with severe disruptions and partial paralysis as many industries shut down and the armed forces and volunteers mobilized for the far more urgent effort of finding survivors, evacuating residents near the stricken power plants and caring for the victims of the 8.9 magnitude quake that struck on Friday.
The disaster has left more than 10,000 people dead, many thousands homeless and millions without water, power, heat or transportation.
The most urgent worries concerned the failures at two reactors at the Fukushima Daiichi nuclear power plant, where engineers were still struggling to avert meltdowns and where some radiation had already leaked. An explosion at one of the reactors on Monday did not appear to have harmed it, Japanese officials said.
Fukushima Daiichi and another power station, Fukushima Daiini, about 10 miles away, have been under a state of emergency since the quake. The collective anxiety about Japan caused a rout in the Japanese stock market on Monday morning, with the main index falling 5.5 percent, the worst drop in three years.
Worried about the severe strains on the banking and financial systems, the Bank of Japan pumped about $86 billion into the economy on Monday, and the government was discussing an emergency tax increase to help finance relief and recovery work.
The Tokyo Electric Power Company, which operates the country’s crippled nuclear power grid, announced a series of rotating blackouts to conserve electricity — the first controlled power cuts in Japan in 60 years.
The death toll was certain to climb as searchers began to reach coastal villages that essentially vanished under the first muddy surge of the tsunami, which struck the nation’s northern Pacific coast near the port city of Sendai. In one town alone, the port of Minamisanriku, a senior police official said the number of dead would “certainly be more than 10,000.” That is more than half the town’s population of 17,000.
Prime Minister Naoto Kan told a news conference in Tokyo late Sunday: “I think that the earthquake, tsunami and the situation at our nuclear reactors makes up the worst crisis in the 65 years since the war. If the nation works together, we will overcome.”
The government ordered 100,000 troops — nearly half the country’s active military force and the largest mobilization in postwar Japan — to take part in the relief effort. An American naval strike group led by the nuclear-powered aircraft carrier Ronald Reagan also arrived off Japan on Sunday to help with refueling, supply and rescue duties.
The quake and tsunami did not reach Japan’s industrial heartland, although economists said the power blackouts could affect industrial production — notably carmakers, electronics manufacturers and steel plants — and interrupt the nation’s famously efficient supply chain. Tourism was also bound to plummet, as the United States, France and other nations urged citizens to avoid traveling to Japan.
AIR Worldwide, a risk consultant in Boston, said its disaster models estimated property damage to be as high as $35 billion. The company said 70 percent of residential construction in Japan was wood, and earthquake insurance was not widely used.
Amid the despair and the worry over an unrelenting series of strong aftershocks, there was one bright moment when the Japanese Navy rescued a 60-year-old man who had been floating at sea for two days.
The man, Hiromitsu Arakawa, clung to the roof of his tiny home in the town of Minamisoma after it was torn from its foundations by the first wave of the tsunami, the Defense Ministry said. He saw his wife slip away in the deluge, but he hung on as the house drifted away. He was discovered late Sunday morning, still on his roof, nine miles south of the town and nine miles out to sea.
The quake was the strongest to hit Japan, which sits astride the “ring of fire” that designates the most violent seismic activity in the Pacific Basin.
About 80,000 people were ordered to evacuate danger zones around the two compromised atomic facilities in Fukushima Prefecture. Japanese officials reported that 22 people showed signs of radiation exposure and as many as 170 were feared to have been exposed, including some who had been outside one of the plants waiting to be evacuated. Three workers were suffering what officials described as full-blown radiation sickness.
In a televised address the trade minister, Banri Kaieda, asked businesses to limit power use as they returned to operation on Monday. He asked specifically for nighttime cutbacks of lights and heating. The power company said the blackouts would affect three million customers, including homes and factories.
The Japan Railways Group cut operations at six of its commuters lines and two bullet trains to 20 percent of normal to conserve electricity.
Tokyo and central Japan continued to be struck by aftershocks off the eastern coast of Honshu Island. A long tremor registering 6.2 caused buildings in central Tokyo to sway dramatically on Sunday morning.
Search teams from more than a dozen nations were bound for Japan, including a unit from New Zealand, which suffered a devastating quake last month in Christchurch. A Japanese team that had been working in New Zealand was called home.
A combined search squad from Los Angeles County and Fairfax County, Va., arrived from the United States with 150 people and a dozen dogs that would help in the search for bodies.
Assistance teams were also expected from China and South Korea, two of Japan’s most bitter rivals.
Tokyo’s acceptance of help — along with a parade of senior officials who offered updates at televised news conferences on Sunday — was in marked contrast to the government’s policies after the 1995 Kobe earthquake, which killed more than 6,000 people. Japan refused most offers of aid at the time, restricted foreign aid operations and offered little information about the disaster.
Here in Sendai, a city of roughly a million people near the center of the catastrophe, many buildings cracked but none had collapsed. Still, city officials said that more than 500,000 households and businesses were without water, and many more lacked electricity as well.
Soldiers surrounded Sendai’s city hall, where officials were using two floors to shelter evacuees and treat the injured, using power drawn from a generator. Thousands of residents sought refuge inside and waited anxiously for word from their relatives. A line of people waited outside with plastic bottles and buckets in hand to collect water from a pump.
Masaki Kokubum, 35, has been living at the city hall since the quake. He had worked at a supermarket, and his neighborhood lost power and water. He said he had not slept in three days.
“I can’t sleep,” he said as he sat in a chair in a hallway. “I just sit here and wait.”