MIYAKO, Japan » To Ryo Orui, a high school junior, almost as frightening as the trembling of the earth or the wailing of tsunami sirens was the loss of his cellphone signal. When Japan’s big earthquake struck, Orui said, he felt a wave of panic at not being able to instantly contact loved ones, or get news on what was happening.

So he jumped on his bicycle and pedaled around this tsunami-ravaged fishing port on Japan’s rugged northern coast to check on the safety of his parents and classmates.

"I felt so isolated," said Orui, 17. "You don’t realize how much you rely on something until you lose it."

Among the casualties of the magnitude 9.0 earthquake on March 11 were modern communications networks, which proved surprisingly vulnerable. Millions of people in eastern and northern Japan, including Tokyo, lost some or all cellphone service. A total of 1.3 million land lines and fiber-optic links also went dead.

While those interruptions pale in comparison to the human tragedy of the earthquake and tsunami 27,000 people are dead or missing the fragility of modern communications has emerged as one of the catastrophe’s sobering lessons.

In a technology-crazed nation where many people were glued to cellphones and accustomed to the Internet’s nearly instantaneous access to information, being cut off has proved disorienting and frightening. Many local governments in the hardest-hit areas, desperate to reach residents with important emergency information, have reached into the past for more tried-and-true means of communication, including radios, newspapers and even human messengers.

"When cellphones went down, there was paralysis and panic," said Shoji Ogasawara, the head of emergency communications at Miyako’s City Hall, where the tsunami filled the first floor with foul-smelling mud. "Everyone was running around asking, ‘What happened to the nuclear plant? What happened to our town?"’

Throughout the country, people have turned to low-tech alternatives in their sometimes frantic search for news of loved ones in quake-affected areas. They have posted notices on bulletin boards and recorded tearful pleas on television. Even in Tokyo, normally a hi-tech showplace for the nation, residents have turned to improvisation.

A small shop near Tokyo Station that specializes in products from Fukushima Prefecture, the site of the stricken nuclear plant, suddenly founded itself crowded by people who came because it carries newspapers from that region, which are hard to find elsewhere in Tokyo. About 500 people now visit the store each day to scan the newspapers’ lists of names of those in Fukushima’s refugee shelters, a manager, Yutaka Suzuki, said.

While Tokyo’s cellphone service has been restored, much of Miyako remains cut off from cellphones and the Internet.

The city’s main way of releasing the names of survivors of the disaster is to tape printed lists on the walls of City Hall. Lacking e-mail, officials deliver by hand these lists to other city offices for posting.

To warn residents in the event of another tsunami, Miyako relies on a network of more than 300 outdoor loudspeakers and sirens, some of which date to the end of World War II.

Waves from the 25-foot tsunami also knocked out roads and electricity. As a result, city officials say, radio has proven to be the most reliable medium to get information to survivors scattered over a wide area.

Many shelters are also printing their own mini-newspapers. In his free time, Katsutoshi Maekawa, a city employee who works at the Sokei Elementary shelter, produces the Sokei Community Daily, a one-page newsletter that tells refugees here about events at the shelter and surrounding neighborhood.

"Paper can be read right away and passed around," Maekawa, 34, said. "No turning on a monitor, no online connections, no keyboards." Even younger Japanese like Orui, who prefer to go online, say weeks of being cut off from the Internet have made them realize how reliant they had become on new technologies that could be so easily disrupted.

"Cellphones and the Internet were the first things to go," said Eri Itobata, 17, a high school student who volunteered to help Miyako Disaster radio. "Thankfully the old technologies were still around."

© 2011 The New York Times Company