No water, power or food in vast swaths of Japan. Death figures might go up as high as 10,000.

TAGAJO, Japan – People across a devastated swath of Japan suffered for a third day Sunday without water, electricity and proper food, as the country grappled with the enormity of a massive earthquake and tsunami that left more than 10,000 people dead in one area alone.

Japan's prime minister called the crisis the most severe challenge the nation has faced since World War II, as the grim situation worsened. Friday's disasters damaged a series of nuclear reactors, potentially sending one through a partial meltdown and adding radiation contamination to the fears of an unsettled public.

Temperatures began sinking toward freezing, compounding the misery of survivors along hundreds of miles (kilometers) of the northeastern coast battered by the tsunami that smashed inland with breathtaking fury. Rescuers pulled bodies from mud-covered jumbles of wrecked houses, shattered tree trunks, twisted cars and tangled power lines while survivors examined the ruined remains.

In Rikusentakata, a port city of over 20,000 virtually wiped out by the tsunami, Etsuko Koyama escaped the water rushing through the third flood of her home but lost her grip on her daughter's hand and has not found her.

"I haven't given up hope yet," Koyama told public broadcaster NHK, wiping tears from her eyes. "I saved myself, but I couldn't save my daughter."

To the south, in Miyagi prefecture, or state, the police chief told a gathering of disaster relief officials that his estimate for deaths was more than 10,000, police spokesman Go Sugawara told The Associated Press. Miyagi has a population of 2.3 million and is one of the three prefectures hardest hit in Friday's disaster. Fewer than 400 people have officially been confirmed as dead in Miyagi.

According to officials, more than 1,400 people were killed — including 200 people whose bodies were found Sunday along the coast — and more than 1,000 were missing in the disasters. Another 1,700 were injured.

Japanese officials raised their estimate Sunday of the quake's magnitude to 9.0, a notch above the U.S. Geological Survey's reading of 8.9. Either way, it was the strongest quake ever recorded in Japan

For Japan, one of the world's leading economies with ultramodern infrastructure, the disasters plunged ordinary life into nearly unimaginable deprivation.

Hundreds of thousands of hungry survivors huddled in darkened emergency centers that were cut off from rescuers, aid and electricity. At least 1.4 million households had gone without water since the quake struck and some 1.9 million households were without electricity.

While the government doubled the number of soldiers deployed in the aid effort to 100,000 and sent 120,000 blankets, 120,000 bottles of water and 29,000 gallons (110,000 liters) of gasoline plus food to the affected areas, Prime Minister Naoto Kan said electricity would take days to restore. In the meantime, he said, electricity would be rationed with rolling blackouts to several cities, including Tokyo.

"This is Japan's most severe crisis since the war ended 65 years ago," Kan told reporters, adding that Japan's future would be decided by its response.

In a rare piece of good news, the Defense Ministry said a military vessel on Sunday rescued a 60-year-old man floating off the coast of Fukushima on the roof of his house after he and his wife were swept away in the tsunami. He was in good condition. His wife did not survive.

A young man described what ran through his mind before he escaped in a separate rescue. "I thought to myself, ah, this is how I will die," Tatsuro Ishikawa, his face bruised and cut, told NHK as he sat in striped hospital pajamas.

Dozens of countries have offered assistance. Two U.S. aircraft carrier groups were off Japan's coast and ready to provide assistance. Helicopters were flying from one of the carriers, the USS Ronald Reagan, delivering food and water in Miyagi.

Two other U.S. rescue teams of 72 personnel each and rescue dogs arrived Sunday, as did a five-dog team from Singapore.

Still, large areas of the countryside remained surrounded by water and unreachable. Fuel stations were closed, though, at some, cars waited in lines hundreds of vehicles long.

The United States and a several countries in Europe urged their citizens to avoid travel to Japan. France took the added step of suggesting people leave Tokyo in case radiation reached the city.