Tune in to "Piers Morgan Tonight" at 9 ET for the latest on Japan's nuclear plant and "Nance Grace" at 8 ET on HLN for more on the rescue effort in Japan as survivors are still emerging.

Kamaishi, Japan (CNN) -- Toyoko Numayama walks from town to town, clutching a photograph of her husband and praying someone recognizes him.

"Of course, I have to have hope," she says.

Missing-persons notices are like wallpaper at the city office in this quake-ravaged coastal town in northeastern Japan. Signs posted show pictures of mothers, grandmothers and husbands.

Survivors sift through evacuation center and hospital logs as the government's tally of the missing grows daily. By 9 a.m. Tuesday, officials said they still had not accounted for 12,664 people, and police say they fear at least half of those are dead.

A glimmer of optimism surged Sunday after rescuers found a grandmother and her teenage grandson, who had been trapped for nine days in their Ishinokmaki home. But happy reunions are increasingly rare.

Japan's national police say 8,928 people are confirmed dead after a 9.0-magnitude earthquake and devastating tsunami March 11 pulverized entire towns, leaving broken wood beams and massive piles of rubble where organized neighborhoods once stood.

All the rooms are empty at the Ishinomaki City Hospital. There are no doctors or nurses or patients.

Along the cold, dark hallways, half-eaten food remains on trays. Cell phones and shoes are on the floor. A message written with bright orange tape on the hospital's roof says: "SOS."

The tsunami sent water rushing into the first floor. Patients panicked, surgeon Dr. Yashuhiko Yamiyama said, and at least two people died in the lobby.

Helicopters arrived four days later, lifting doctors and patients strapped to stretchers to safety. But it is impossible to know how many people perished when the waters rushed in, or how many were swept away.

Akihito Yamaguchi doesn't know what happened to his 71-year-old father after the tsunami hit Kamaishi.

"I held my father above the water, but the force of the tsunami was too strong. I couldn't hold on," he says.

Now, Yamaguchi flips through the pages of a soggy photo album from his childhood, pointing at pictures of his parents.

He says he won't leave what's left of his house. He thinks his mother may be buried in the rubble of the first floor.

Across the country, some 380,000 people are staying at 2,200 shelters, Kyodo News reported.

Many of them are frail and elderly. Officials say that in the hardest hit region, 30 percent of the population is over the age of 65.

"There are so many of them, particularly in this area," Dr. Takahiko Naruko said. "The number of young people has been falling for years."

Emiko Sato sits in a school gym with her 93-year-old grandmother and her 73-year-old father.

She says both of them need constant medical care that just isn't available. Ever since the tsunami, her grandmother only responds to questions with moans.

"It's really difficult, but when I look around this room, it's the same for everybody," she says.

Even in parts of the country that were not directly impacted by the quake, concerns are high -- particularly as workers scramble to cool down fuel rods to prevent a full meltdown at the Fukushima Daiichi nuclear plant.

Akira Shioi of Kawasaki said he's changed his daily routine so he can keep up with the latest developments, carrying a radio with him 24 hours a day so he can listen to the news.

He said he is following closely updates about radioactive contamination in milk and spinach near the plant, but feels confident that the government is monitoring data to protect the population.

"I don't feel risk at this moment. ... I think it's under control," he said.

Efforts to cool down reactors at the plant saw a setback Monday as officials evacuated workers after gray smoke spewed from the building housing the plant's No. 3 reactor. Japan's nuclear safety agency said it was still investigating what caused the smoke, and that preliminary readings indicated radiation levels had not spiked.

A World Health Organization official said Monday that the detection of high levels of radioactivity in certain foods -- and the nation's subsequent clampdown on their sales -- signals the food safety situation is "more serious" than originally thought.

Chief Cabinet Secretary Yukio Edano urged people "to behave and act calmly" even as officials banned the shipping of some products.

But some have said the government's announcements do not reassure them.

"I'm afraid of the radiation because it's something I can't see," said Maya Nagase of Tokyo. "And we just can't trust the information that we're getting."

CNN's Kyung Lah, Gary Tuchman, Anna Coren and Catherine E. Shoichet contributed to this report.