It is every parent's nightmare: a normally reliable child sets off on a journey, then vanishes without a trace. But through the power of social media, a small army of thousands of volunteers produced a happy ending in the case of Jacob Boehm.

Boehm, 22, a senior at Stanford University, had gone to Japan in June with the Stanford Chamber Chorale. When the rest of the singers headed home, he continued to travel, carrying his U.S. and German passports.

Like most of his peers at elite universities, he was well plugged in to the world around him, posting regular updates every two to three days on his travels through Southeast Asia. By Aug. 13, he had announced through his Google+ page that he was in Malaysia.

Then nothing for a week.

Worried, his parents, Bruce Boehm and Nancy Luberoff, got in touch with U.S. and German consular officials in Malaysia and sent emails to 12 of his friends. The message went viral. On Facebook, more than 5,000 people subscribed to one of two pages dedicated to the hunt. On Twitter, #JacobBoehm became a trending topic in the San Francisco Bay Area, the home of Stanford.

The first Facebook page was created shortly before 11 a.m. Friday, San Francisco time, by Julian Kusnadi, a fellow member of the chorale. People immediately started joining in, offering suggestions, encouragement and prayers. One suggested reaching out to current and former Stanford students who lived in Malaysia or hailed from there.

Another posted a close-up photo showing just Boehm's face.

Misha Nasrollahzadeh, doing a summer internship at Facebook, contacted its "safety team," which offered to run free advertising promoting the page within Malaysia. And that was just in the first 10 minutes.

At that point, a second page, which became the main source of information, appeared.

A missing-person flier was posted in English, then translated by someone else into Malay.

Celeste Brash, who writes the Lonely Planet guide for the area, noted that the village where Boehm had last been seen, Jerantut, is a gateway to Taman Negara, a jungle area that is a vast national park. "Is it possible he went on a long jungle trek?" she wrote, offering local contact information.

Boehm's father suggested it was unlikely that he would make an unannounced multiday trip into the jungle, as it was "not his sort of thing."

Help — and new worries

Where social media soothed her that a search plan was in action, Boehm's mother, Nancy Luberoff, said it also fueled her dread. A recent post noted if he went into the jungle "he could be a goner and no one would know."

One Facebooker stoked another fear: "Your child will absolutely hate you for doing this to him when he gets back."

More suggestions and offers of help came forth, including one from Timothy Tam, a Stanford student whose father works in the office of Prime Minister Najib Razak of Malaysia.

The hours passed as the search went into high gear in Malaysia, focusing on the national park.

Finally, at 10 p.m. Friday San Francisco time, came a piece of news from the U.S. Embassy: "The park rangers informed us your son checked into the Tembeling River View chalet in the town of Kuala Tahan (approximately 1 hour driving north of Jerantut) on August 15th and checked out on the 17th. He did not obtain a permit to enter Taman Negara national forest. The rangers will continue searching. We will continue checking with them and other contacts."

The circle widened via Twitter and Reddit.

Several Malaysians who had joined the effort on Facebook noted that anyone entering Taman Negara is required to have a permit and a guide, and that people without guides occasionally get lost. And there is generally no cellphone or Internet access.

A search team of park rangers was dispatched. It took 11 hours to find Boehm, who was hiking with a guided group. The rangers' jungle trek was made more difficult because it is the month of Ramadan, and they are fasting.

"We are so grateful"

At about 8 a.m. San Francisco time Saturday, 21 hours after the first posting on Facebook, Boehm was in communication with U.S. officials via two-way radio. Asked what had happened, he reportedly said, "It's a long story."

Luberoff said in a statement that the "real story" was not her son's disappearance, but rather that "thousands of people worked together to find him."

"We are so grateful for this spontaneous community and outpouring of support," she said. "I hope it becomes a model for others."

"We all wonder, at what point do you start worrying? Do we wait five days, six days, seven days, eight days? No parent knows the answer," she said Saturday. "We do not regret emailing 12 of Jacob's friends just 24 hours ago to ask for help. We just never imagined that over 4,000 people would care enough to help."

Additional information from The San Jose Mercury News