HADENYA, Japan — The colossal wave that swept away this tiny fishing hamlet also washed out nearby bridges, phone lines and cellphone service, leaving survivors shivering and dazed and completely cut off at a hilltop community center.

With no time to mourn for their missing loved ones, they were immediately thrust into the struggle to stay alive in the frigid winter cold, amid a hushed, apocalyptic landscape of wrecked homes, crushed vehicles and stranded boats. They had scant food and fuel and no news from the outside world — not even the scope of the devastation.

On Wednesday, after the Japanese military finally reached them for the first time since the tsunami struck 12 days ago, by erecting makeshift bridges and cutting roads through the debris, they told a remarkable tale of survival that drew uniquely on the tight bonds of their once-tidy village, having quickly reorganized themselves roughly along the lines of their original community: choosing leaders, assigning tasks and helping the young and the weak.

The ability of the people of Hadenya to survive by banding together in a way so exemplary of Japan’s communal spirit and organizing abilities is a story being repeated day to day across the ravaged northern coastline, where the deadly earthquake and tsunami left survivors fending for themselves in isolated pockets. Some are still awaiting relief.