Hopes for finding survivors trapped under rubble began to fade 48 hours after Nepal’s worst earthquake in decades even as rescuers ferried scores of climbers trapped on Mount Everest to safety.

Governments from around the globe rushed to aid one of Asia’s poorest economies following a magnitude 7.8 earthquake on Saturday, April 25, that has killed more than 3,733 people. International relief agencies warned of water-borne diseases spreading as millions of residents wary of aftershocks camped outdoors.

“It seems very difficult to find survivors now,” Rameshwor Dangal, joint secretary at Nepal’s Home Ministry, said on Monday in Kathmandu, the capital. “Those trapped could be in the thousands, but it’s difficult to estimate right now. Millions are homeless.”

Makeshift tents popped up all over Kathmandu, where orange and blue tarps hung on hundreds of buildings at risk of collapse. Hundreds of motorists lined up at petrol stations in the city, raising fears of a fuel shortage that could hinder efforts to provide relief in more remote areas.

At least 19 foreigners including a Google Inc. executive died on Everest after the earthquake. Helicopters evacuated almost all of the 180 climbers who were stuck at Camp 1 and Camp 2 on Everest after the route back to base camp was blocked in an avalanche, Ang Tshering Sherpa, president of the Nepal Mountaineering Association, said by phone on Monday.

Time Running Out

“They are all in good health,” Sherpa said, adding that 700 climbers are still at base camp and the route to Camp 1 is being repaired.

Nepalese authorities appealed for tents, food, blankets and medicines to help those without homes throughout the Himalayan nation. Rains have slowed power restoration and other relief efforts, including the clearing away of corpses.

“Time is of the essence for the search and rescue operations,” Valerie Amos, the United Nations under secretary- general for humanitarian affairs, said in a statement. Many people have slept in the open for two nights and require food, water and emergency shelter, while at least 940,000 children live in areas severely affected by the earthquake, the UN said.

About 3,000 patients were strewn in hallways, benches and courtyards at the 600-bed Teaching Hospital in Kathmandu, with staff struggling to treat all the wounded. Medical waste spilled out of a trash can next to a women on a stretcher as doctors looked at X-rays outdoors.

Rebuilding Costs

Among the injured were children who suffered from broken bones, with some needing amputations. Many patients had open wounds that doctors are unable to treat due to a lack of manpower and supplies, raising the risk of water-borne diseases.

Suresh Kayastha, a doctor at the hospital, said the situation outside the capital was even worse.

“No rescuers have gone outside the valley,” Kayastha said. “There is no government supply of aid in these regions.”

The International Monetary Fund, humanitarian groups and governments from China to India to Israel rushed to provide assistance to Nepal. Rebuilding costs could “easily exceed” $5 billion, which would be about 20 percent of Nepal’s gross domestic product, Rajiv Biswas, chief Asia economist at IHS, told Bloomberg Television.

“This is a very catastrophic event in a very poor nation,” Biswas said on Monday. “The cost of reconstruction over the next few years will be massive.”

Rain Forecast

Tourism is a key economic driver for Nepal, which has a gross domestic product that is smaller than any of the 50 U.S. states. Its 28 million people have the lowest spending power of any Asian country apart from Afghanistan, IMF statistics show.

Hundreds of people attempt to reach Everest’s summit each year, typically paying a minimum of $30,000 per person and often far more for the privilege, according to an estimate by Outside magazine. The rising numbers of climbers has drawn complaints about overcrowding, littering and heightened danger. April is a peak month for climbing.

Kathmandu’s international airport closed temporarily after the initial quake and again after a 6.7 magnitude aftershock on Sunday. Television images showed tourists camped outside the airport awaiting flights to leave.

Widespread rains are forecast to hit Nepal, threatening to further hinder relief efforts, the India Meteorological Department said on Sunday. It warned citizens to be beware of possible landslides.

“The weather is not helping,” Renaud Meyer, country manager for the UN Development Program, told Bloomberg Television. “In normal circumstances it can take several days to reach out to the villages. Now with the rain plus the quake it’s a source of major concern to even have an assessment of the situation in those remote villages.”

–With assistance from Abhishek Shanker in Mumbai and Bibhudatta Pradhan and Natalie Obiko Pearson in New Delhi.