By MALCOLM FOSTER
TOKYO (AP) â€” For more than two terrifying, seemingly endless minutes Friday, the most powerful earthquake ever recorded in Japan shook apart homes and buildings, cracked open highways and unnerved even those who have learned to live with swaying skyscrapers. Then came a devastating tsunami that slammed into northeastern Japan and killed hundreds of people.
The violent wall of water swept away houses, cars and ships. Fires burned out of control. Power to cooling systems at two nuclear power plants was knocked out, forcing thousands of nearby residents to be evacuated. A boat was caught in the vortex of a whirlpool at sea.
The death toll rose steadily throughout the day, but the true extent of the disaster was not known because roads to the worst-hit areas were washed away or blocked by debris and airports were closed.
After dawn Saturday, the scale of destruction became clearer.
Aerial scenes of the town of Ofunato showed homes and warehouses in ruins. Sludge and high water spread over acres of land, with people seeking refuge on roofs of partially submerged buildings. At one school, a large white â€śSOSâ€ť had been spelled out in English.
Chief Cabinet Secretary Yukio Edano said an initial assessment found â€śenormous damage,â€ť adding that the Defense Ministry was sending troops to the hardest-hit region.
President Barack Obama pledged U.S. assistance following what he called a potentially â€ścatastrophicâ€ť disaster. He said one U.S. aircraft carrier is already in Japan and a second was on its way. A U.S. ship was also heading to the Marianas Islands to assist as needed, he added.
The entire Pacific had been put on alert â€” including coastal areas of South America, Canada and Alaska â€” but waves were not as bad as expected.
The magnitude-8.9 offshore quake struck at 2:46 p.m. local time and was the biggest to hit Japan since record-keeping began in the late 1800s. It ranked as the fifth-largest earthquake in the world since 1900 and was nearly 8,000 times stronger than one that devastated Christchurch, New Zealand, last month, scientists said.
The quake shook dozens of cities and villages along a 1,300-mile (2,100-kilometer) stretch of coast and tall buildings swayed in Tokyo, hundreds of miles from the epicenter. Prime Minister Naoto Kan was attending a parliamentary session at the time.
â€śI thought I was going to die,â€ť said Tokyo marketing employee Koto Fujikawa. â€śIt felt like the whole structure was collapsing.â€ť
Fujikawa, 28, was riding a monorail when the quake hit and had to later pick her way along narrow, elevated tracks to the nearest station.
Minutes later, the earthquake unleashed a 23-foot (seven-meter) tsunami along the northeastern coast of Japan near the coastal city of Sendai in Miyagi prefecture. The U.S. Geological Survey said that after the intial huge quake, there were 123 aftershocks off Japanâ€™s main island of Honshu, 110 of them of magnitude 5.0 or higher
Large fishing boats and other vessels rode the high waves ashore, slamming against overpasses or scraping under them and snapping power lines along the way. A fleet of partially submerged cars bobbed in the water. Ships anchored in ports crashed against each other.
The tsunami roared over embankments, washing anything in its path inland before reversing direction and carrying the cars, homes and other debris out to sea. Flames shot from some of the homes, apparently from burst gas pipes.
Waves of muddy waters flowed over farms near Sendai, carrying buildings, some of them ablaze. Drivers attempted to flee. The tarmac at Sendaiâ€™s airport was inundated with thick, muddy debris that included cars, trucks, buses and even light planes.
Highways to the worst-hit coastal areas buckled. Telephone lines snapped. Train service was suspended in northeastern Japan and in Tokyo, which normally serves 10 million people a day. Untold numbers of people were stranded in stations or roaming the streets. Tokyoâ€™s Narita airport was closed indefinitely.
Police said 200-300 bodies were found in Sendai, although the official casualty toll was 185 killed, 741 missing and 948 injured.
A ship with 80 dock workers was swept away from a shipyard in Miyagi prefecture. All on the ship was believed to be safe, although the vessel had sprung a leak and was taking on some water, Japanâ€™s coast guard said.
In the coastal town of Minami-soma, about 1,800 houses were destroyed or ravaged, a Defense Ministry spokeswoman said. Fire burned well past dark in a large section of Kesennuma, a city of 70,000 people in Miyagi.
A resident in Miyagi who had been stranded on his roof, surrounded by water, mud and fallen trees, was rescued by a Self-Defense Force helicopter Saturday morning, TV video showed.
Japan declared its first-ever states of emergency for five nuclear reactors at two power plants after the units lost cooling ability in the aftermath of the earthquake, and workers struggled to prevent meltdowns.
The earthquake knocked out power at the Fukushima Daiichi plant, and because a backup generator failed, the cooling system was unable to supply water to cool the 460-megawatt No. 1 reactor. Although a backup cooling system is being used, Japanâ€™s nuclear safety agency said pressure inside the reactor had risen to 1.5 times the level considered normal.
Authorities said radiation levels had jumped 1,000 times normal inside Unit 1 and were measured at eight times normal outside the plant. They expanded an earlier evacuation zone more than threefold, from 3 kilometers to 10 kilometers (2 miles to 6.2 miles). About 3,000 people were urged to leave their homes in the first announcement.
Tokyo Electric Power Co. warned of power shortages and an â€śextremely challenging situation in power supply for a while.â€ť
The utility, which also operates reactors at the nearby Fukushima Daini plant, later confirmed that cooling ability had been lost at three of four reactors there, as well as a second Fukushima Daiichi unit. The government promptly declared a state of emergency there as well.
The level outside the 40-year-old plant in Onahama, a city about 170 miles (270 kilometers) northeast of Tokyo, is still considered very low compared to the annual exposure limit, said Ryohei Shiomi, an official with the Japan Nuclear and Industrial Safety Agency. It would take 70 days of standing at the gate to reach the limit, he said.
The Defense Ministry said it had sent troops trained to deal with chemical disasters to the plants in case of a radiation leak.
An American working at the Fukushima Daiichi facility said the whole building shook and debris fell from the ceiling. Danny Eudy, 52, a technician employed by Texas-based Atlantic Plant Maintenance, and his colleagues escaped the building just as the tsunami hit, his wife told The Associated Press.
â€śHe walked through so much glass that his feet were cut. It slowed him down,â€ť said Pineville, Louisiana, resident Janie Eudy, who spoke to her husband by phone after the quake.
The group watched homes and vehicles carried away in the wave and found their hotel mostly destroyed when they reached it.
A large fire erupted at the Cosmo oil refinery in the city of Ichihara and burned out of control with 100-foot (30-meter) flames whipping into the sky.