In 2015 a violent earthquake shook Nepal, killing thousands across the country. In its wake, climbing teams at Mt Everest were hit by a deadly avalanche that destroyed Base Camp and caused the deaths of nearly twenty people. Anthea Fisher was there and recalls the avalanche and the aftermath for Eyewitness producer Justin Gregory.

"You could actually see the avalanche heading towards us. It was like an explosion. I wasn't sure if I would survive" - Anthea Fisher.

The day of 25 April 2015 began early for Everest Base Camp manager Anthea Fisher. Back home in New Zealand it was ANZAC Day, but high in the Himalayas, Anthea was thinking only of her job.

The Wanaka resident was working for Kiwi mountain guiding company Adventure Consultants and this was her first time on the highest mountain in the world.

The team had been at Base Camp for about three weeks and Anthea had got up that morning, while it was still dark, to see off her climbers as they began their first trek up to Camp 1. With most of her colleagues and clients away, she was enjoying the relative peace and quiet of a nearly empty base camp.

"I was actually having a little late morning nap."

"Just because I could! Because I knew I wouldn't be disturbed by questions or having to organise anything."

"So I was in my tent when the earthquake struck."

The 7.8 magnitude earthquake hit at 11.56am and lasted for 50 seconds. The epicentre was near the Kathmandu valley, just 160kms northwest of Everest.

But while the shaking was over in less than a minute, the real danger to Anthea and others at Base Camp was about to begin. An ice cliff between the Pumori, Lingtren and Khumbutse mountains above them had collapsed, causing huge chunks of ice to fall hundreds of metres to the valley floor below.

"It sounded like the valley was falling down around us."

The force of the ice cliffs collapsing shattered the rocks beneath them. The resulting avalanche was a deadly mix of snow, ice and razor-sharp shards of broken rock - and it hit Base Camp within seconds.

"You could actually see the avalanche heading towards us. It was like an explosion. I wasn't sure if I would survive."

Anthea took shelter in a large nearby tent, but had the presence of mind to stay in the doorway to avoid being suffocated as it collapsed under the pounding of rocks and snow.

"I remember thinking 'I hope this stops soon because I don't know how much longer I can take this for'."

Several large avalanches hit that day. One, in the nearby Langtang Valley, killed more than 300 people. Nepal's capital, Kathmandu, was also hit hard…

Go to this episode on rnz.co.nz for more details