Kathmandu, Nepal: A 7.8-magnitude quake struck Nepal at 0611 GMT on Saturday 25 April 2015, flattening large parts of the capital Kathmandu and causing devastation across the impoverished Himalayan nation.

Here are the key facts about Nepal's worst natural disaster in 80 years.

Death toll

- 5,057 people are known to have died in Nepal alone

- Another 8,000 were injured

- 18 climbers died at Mount Everest base camp when the quake sparked an avalanche

- Two Americans, an Australian, a Japanese and a Chinese national were among the victims on the mountain

- 74 people were killed in India

- In China, 25 lost their lives, according to the ministry of civil affairs in Tibet

Survivors

- The United Nations estimates that eight million people have been affected

- 1.3 million children are in urgent need of humanitarian aid, according to the UN

- Some 1.4 million people require emergency food aid, the World Food Programme says

Aid

- Dozens of countries from around the world have rushed to pledge money. The most significant sums include:

- $15 million from the UN's emergency fund

- $15 million total contributed by Britain

- $10 million pledged by the United States

- $8.4 million from Japan, according to local media

- And $4.7 million from Australia

Reconstruction

- The UN Office for the Coordination of Humanitarian Affairs (OCHA) estimates 530,000 houses were damaged

- Another 70,000 were destroyed, OCHA said

- The UN agency said that up to 90 percent of health facilities in four districts were severely damaged

- Some 16,000 schools were damaged, according to OCHA

- Business research IHS estimates that reconstruction costs could top $5 billion or around 20 percent of the country's GDP