Sirens mark memorial for nation in state of alarm

>>> in this country the federal government says no radiation levels of concern have been detected, but for the people of japan , the fear of a nuclear catastrophe is just a part of the story. the extent of the humanitarian crisis is truly staggering. nbc's ann curry reports from akita again tonight on that nation still struggling to cope with this disaster. ann , good evening.

>> reporter: brian, good evening to you. that's right. here are the numbers to date. about 7,000 confirmed dead . nearly 11,000 still missing. and today this disaster-exhausted nation paused for a moment, trying to come to grips with the week that changed it forever. sirens sounded across japan today , and people stopped to mark one week since the earthquake and tsunami shattered thousands of lives. rescuers paused in their work. evacuation centers grew quiet. the prime minister addressed his people. saying we cannot let ourselves be overcome. seven days into this crisis, the destruction in many towns remains so complete, it's now hard to imagine the thriving communities they once were. other cities like tono up north are ghost towns . little damage, but the people are indoors, fearing radiation. another town is struggling to get back on its feet. my colleague, ian williams , is there.

>> reporter: all along this coast there are reminders of the raw power of the tsunami. this fishing boat , one of several ripped from its moorings and simply dumped by the side of the road . this city survived the tsunami better than most, but here more evidence of the toll suffered by japan 's elderly. they're exhausted and shaken, said the manager of this evacuation center. japan is a rapidly aging society. nowhere more so than in these devastated coastal communities. and the relief effort will increasingly have to focus on them.

>> reporter: the snow and cold are still hindering efforts to get help to the furthest pockets of need. u.s. marines specially trained for bad weather flew supplies into yamagata today. international rescuers have little hope of finding any more survivors, but they are sustained by the measure of comfort they can provide to some anxious loved ones.

>> yesterday we found a young girl 's body, an 8-year-old girl. we were able to send that back to her family.

>> reporter: amid debris, there are what seemed like small miracles . one man found his cousin today after a full week of searching house to house. a woman reunited with her dog after all hope appeared to be lost. small but happy moments in a long week of grief and loss, unlike any nation has ever seen. and international aid is now beginning to reach those areas that are hit hardest by the quake and tsunami, brian, and none too soon.

>> ann , you've done such extraordinary work there. safe travels home. perhaps when you get back we'll have a moment to talk about all the images you took in during your coverage. ann curry in akita, japan , tonight. ann , thanks.