In just two simple sentences, in separate conversations, they gave voice to the many Nepalis who have seen the lives they had built wiped away in seconds.

“Everything is gone,” said Anju Shakya, a shopkeeper.

Anushka Tamang, a janitor, said, “I don’t know what to do next.”

The roaring cascade of mud that on Wednesday carried away or buried their loved ones, homes, businesses and schools left countless people struggling with the same urgent questions: What can I eat, where can I sleep and what can I salvage? And what happens then?

Ms. Tamang, 29, improvised a makeshift path to make the short but perilous walk to the home she had fled in Devighat, a town in central Nepal. She walked on a fallen tree trunk, a tin plank from a roof and the concrete foundation of the ruins of a house, avoiding the quicksand and stepping quickly through muddy patches in her bare feet.

Inside her partly buried home, Ms. Tamang found the silver suitcase that she rarely opened with her dressy saris, stuck in her door and covered in mud, but intact. She located some of her 6-year-old daughter’s clothes that the sludge, four feet deep, had not reached because they hung from her ceiling. She also spotted her cylinders of cooking gas — one empty, one partly full — that might fetch around $14 each.

She and her brother dragged the haul to a nearby school that her daughter attended and where she worked as a janitor. She planned to stay there for a few days with her belongings. How they will live after the immediate crisis is anyone’s guess.

About 500 people are confirmed killed in the flash flood, and nearly 2,000 are reported missing, numbers that are sure to rise given the immensity of the disaster. According to early estimates, the catastrophe is expected to cost the economy, which is largely dependent on tourism, billions of dollars. Repairing and building roads, bridges and power lines is expected to cost hundreds of millions of dollars, if not more.

Rescued people have been sent to hospitals and relief camps, and the government and nonprofit groups have begun building temporary shelters and delivering meals to them.

At the moment, delivering food and water to people and providing temporary shelter are the top priorities, said Hiralal Tamrakar, program director of an aid group, Good Neighbors Nepal, which is working with the local government in the town of Bidur, in the district of Nuwakot, one of the more populated regions that suffered extensive damage. Survivors have urgently asked for food, along with clothes, shelter, blankets and other basic needs, he said.

But as survivors grieve missing friends and family and reconcile themselves to the loss of property and valuables, the question of how to rebuild their lives has few answers yet.

“Later on, the government will make the provision, the plan to settle them,” Mr. Tamrakar said.

Until two days ago, Ms. Shakya, 50, ran a jewelry store in Trishuli Bazaar, a bustling market in Bidur, by the Trishuli River. Ms. Shakya said it had taken a lot of effort, but she had managed to make a comfortable life for herself and her family, with good prospects for their future.

She had lived for more than two decades in a three-story home she shared with her son, daughter-in-law and grandson. They had two cars and a motorcycle.

She said her family had amassed about 3.5 kilograms of gold, worth roughly $500,000. She planned to pay for her grandson’s education.

That carefully nurtured life vanished when mud burst through the shop walls on its way to her home.

Ms. Shakya said family members tried to close the windows and doors to keep the slurry out, but within minutes they were forced to flee. They clambered up a hillside to stay above the deadly torrent, and stayed there for two days before army personnel arrived.

The house and cars are gone. The shop is gone. The gold is gone.

Sitting on a cot as army doctors administered care and checked her vitals, Ms. Shakya said she didn’t know how to feel about her future or what to do next. She wore a borrowed T-shirt and a bandage around her left knee, which she sprained scrambling up the hill.

She and her family plan to stay with relatives in Kathmandu, the capital of Nepal, until they decide how to begin pulling together their lives.

“My eyes keep welling up thinking about the wealth we’ve lost,” she said.

“You can’t build a gold shop from scratch,” Ms. Shakya added, still in disbelief that at her age, she had to begin again. “God has taken what he has given us.”