looks like it might get a lot worse:
'MAY BE EXPERIENCING NUCLEAR MELTDOWN'
'HIGH POSSIBILITY' NUCLEAR FUEL RODS MELTING...
Rods Exposed Due to Cooling Failure...
Venting operation suspended due to high levels of radiation...
More than 1,000 people were feared dead and authorities warned a meltdown may be under way at a nuclear plant after a monster tsunami devastated a swathe of northeast Japan.
Reactor cooling systems failed at two generating plants after Friday's record 8.9-magnitude earthquake hit, unleashing a terrifying 10-metre (33-foot) high wave that tore through coastal towns and cities, destroying all in its path.
Radiation 1,000 times above normal was detected in the control room of one nuclear plant, although authorities said levels outside the facility's gates were only eight times above normal, spelling "no immediate health hazard."
But officials warned one of the plants, just 250 kilometres northeast of Tokyo, "may be experiencing nuclear meltdown," Kyodo and Jiji reported.
Tens of thousands of people were evacuated from around the plants as Tokyo Electric Power, which runs the facilities, said it had released some radioactive vapour at both locations to relieve building reactor pressure.
"We are not in a situation in which residents face health damage," Chief Cabinet Secretary Yukio Edano told reporters, according to Jiji news agency.
The two nuclear plants affected are the Fukushima No. 1 and No. 2 plants, both located about 250 kilometres (160 miles) northeast of Tokyo.
The atomic emergency came as the country struggled to assess the full extent of the devastation wreaked by the massive tsunami, which was unleashed by the strongest quake ever recorded in Japan off the eastern coast.
The towering wall of water pulverised the northeastern city of Sendai, where police reportedly said 200-300 bodies had been found on the coast.
More than 215,000 people were in
emergency shelters, police said.
The full scale of those left homeless was believed to be much higher, with police saying they had not received a tally from
Miyagi prefecture, the hard-hit province that is home to Sendai.
"What used to be residential areas were mostly swept away in many coastal areas and fires are still blazing there," Prime Minister Naoto Kan said after seeing the damage with his own eyes by helicopter.
The unstoppable black tide picked up
shipping containers, wrecked cars and the debris of shattered homes and crashed through the streets of Sendai and across open fields, forming a mud slick that covered swathes of land.
The police said 413 people had been confirmed dead and 784 were missing, with 1,128 injured in the disaster but the toll was expected to rise sharply.
"It is believed that more than 1,000 people have lost their lives," said Edano, the prime minister's right-hand man and top spokesman.
"The damage is so enormous that it will take us much time to gather data," an official at the police agency told AFP.
Authorities said more than 3,000 homes were destroyed or swept away and tens of thousands of people spent the night in
emergency shelters.
The tsunami obliterated Rikuzentakata, a coastal city of some 23,000 people, the Fire and Disaster Management Agency said.
Some 50,000 military and other rescue personnel were pushed into action to spearhead the Herculean rescue and recovery effort with hundreds of ships, aircraft and vehicles headed to the Pacific coast area.
Army helicopters airlifted people off the roof of an elementary school in Watari, Miyagi prefecture.
The towering wave set off alerts across the Pacific, sparking evacuations in Hawaii and on the US West Coast, damaging boats and leaving one man missing.
Chile said it was evacuating coastal areas and Ecuador's state oil company announced it had suspended crude
oil exports due to risks posed by the tsunami.
The
Bank of Japan said it would do its "utmost" to ensure the stability of financial markets after the quake brought huge disruption to key industries.
Major manufacturers including Toyota, Nissan and Sony were forced to suspend production at some sites, raising short-term concerns for the nation's struggling economy.
More than eight million homes lost power, mobile and landline phone systems broke down and gas was cut to more than 300,000 homes, meaning many Japanese could not heat their dark homes during a tense, cold night.
The military mobilised thousands of troops, 300 planes and 40 ships for the
relief effort. An armada of 20 naval destroyers and other vessels headed for the devastated Pacific coast area of Honshu island.
Leading international offers of help, President Barack Obama mobilised the US military to provide
emergency aid after what he called a "simply heartbreaking" disaster.
The United States, which has nearly 40,000 military personnel in Japan, ordered a flotilla including two
aircraft carriers and support ships to the region to provide aid.
"It was the biggest earthquake I have ever felt. I thought I would die," said Sayaka Umezawa, a 22-year-old college student who was visiting the port of Hakodate, which was hit by a two-metre wave.
The quake, which hit at 2:46 pm (0546 GMT) and lasted about two minutes, rattled buildings in greater Tokyo, the world's largest urban area and home to some 30 million people.
Millions were left stranded in the evening after the earthquake shut down the city's vast subway system.
But with small quakes felt every day somewhere in Japan, the country is one of the best prepared to deal with the aftermath of such a calamity.
People take part in regular drills at schools and workplaces to prepare for a tremor on the scale of Friday's "super quake".
"If there is any place in the world ready for a disaster of the scale and scope of this historic calamity, it is Japan," said Stacey White, senior research consultant at the Centre for Strategic and International Studies.
As the
emergency response swung into action, the government urged people to stay near their workplaces rather than risk a long walk home as there was major disruption to air travel.
Bullet train services, like the country's network of advanced nuclear
power plants, are designed to shut down as soon as the earth shakes in one of the world's most quake-prone countries.
In a rare piece of good news, a ship that was earlier reported missing was found swept out to sea and all 81 people aboard were airlifted to safety.
But mostly the picture was one of utter devastation.
The tsunami submerged the runway at Sendai airport, while a process known as liquefaction, caused by the intense shaking of the tremor, turned parts of the ground to liquid.
Hours after the quake struck, TV images showed huge orange balls of flame rolling up into the night sky as fires raged around a petrochemical complex in Sendai. A massive blaze also engulfed an
oil refinery near Tokyo.
Nearly 24 hours after the first, massive quake struck just under 400 kilometres (250 miles) northeast of Tokyo, aftershocks were still rattling the region, including a strong 6.8 magnitude tremor on Saturday.
The
US Geological Survey said more than 100 aftershocks had hit the area.
Japan sits on the "Pacific Ring of Fire" and Tokyo is in one of its most dangerous areas, where three continental plates are slowly grinding against each other, building up enormous seismic pressure.
The government has long warned of the likelihood that a devastating magnitude-eight quake will strike within the next 30 years in the Kanto plains, home to Tokyo's vast urban sprawl.