American families are anxiously awaiting word from loved ones in Nepal, where the catastrophic earthquake over the weekend knocked out power and phone service for whole swaths of the country.
Four Americans are confirmed to have died in the earthquake, all of whom were at a base camp at Mount Everest: Tom Taplin, a Denver-born filmmaker; Marisa Eve Girawong, a Seattle camp doctor; Dan Fredinburg, an engineer for Google; and Vinh B. Truong. The State Department confirmed Truong's death Monday.
Diane Schumacher of Seattle last heard from her daughter Sydney, 19, by text from Kathmandu a week ago, just before she and a friend, Bailey Meola, headed off on a trek through the Langtang Valley, a national park 80 miles from the capital known for spectacular scenery.
They were traveling on their own, part of an adventure between high school and college, but they had plenty of experience in the outdoor life, Schumacher told NBC News by phone Monday.
"They are pretty strong, independent young ladies," she said.
The women were not expected to check back in until Sunday. The earthquake struck Saturday. It was measured at 7.8 magnitude and is known to have killed more than 3,800 people.
It was not clear Monday how many Americans were unaccounted for in Nepal. Dozens of families have registered with the International Red Cross, but that number includes Americans who have been heard from.
Google's Person Finder, which allows users to post under "I'm looking for someone" and "I have information about someone," said it was tracking 6,100 records as of Monday afternoon, but that figure covers people from many countries.
Schumacher said she reached an official at the national park headquarters who told her that the village had been destroyed by an avalanche and that people were moving higher to await rescue.
She said she was worried about reports that people are trapped and running out of food and that the Nepalese military does not have the resources to reach all the people who are trapped.
Meola's mother, Rachelle Brown, told NBC News that she thinks the two may have been near the peaks in Langtang when the earthquake struck.
"We are feeling extremely concerned," she said.
Bailey, also 19, set out to travel the world instead of heading to college right after high school. During her senior year, she was anxious about deciding a course for her life, her mother said.
The trip took Meola from Seattle to Thailand, Singapore, Cambodia and Laos before she met up with Sydney and embarked for Nepal. She has stops in Austria, Italy and Ireland ahead of her. She worked hard to pay for her adventure.
"This was going to solidify what her purpose in life was going to be," her mother said.
Also trekking in Nepal were Jim Lane and Darlene Richmond, from Lummi Island in Washington state.
They have been traveling since April and are due to return home June 2. They last checked in with family on Wednesday, and they were expected to be out of contact for two weeks.
"They were going to be in the mountains, trekking through the Makalu region," said Darlene's sister Doreen.
The couple have traveled to exotic locales in the past for hikes. "That's what they like to do," Doreen said. She said the family is hoping they will check in to reassure everybody.
In Decatur, Georgia, the family of Marty Emanuel told NBC News that they were worried but optimistic. When the quake struck, Emanuel, 71, a retired art professor, was two days into a trek into the Langtang Valley, along Nepal's border with Tibet.
Emanuel is in great shape and trained extensively, hiking Stone Mountain not far from home, said his son Ben. Emanuel was with a local guide whom he met on a previous trip and was already expected to be out of cell range for two weeks.
"He's very resourceful," Ben Emanuel told NBC News. "He's done a lot of wilderness travel, and you have to be self-reliant. Same goes for his guide, Dilli — not only resourceful but well-connected."
Marty Emanuel has traveled in retirement and went to Nepal with his wife a year and a half ago.
"He's gotten attached to Nepal," he son said. "He really, from their first trip, really enjoyed getting to know the people there. He said wonderful things."