Joshi left Nepal when he was 19 to study in the US and then joined Disney. But even though he married and had a child in the US, he felt pulled back to his homeland.

In 2008, he founded Incessant Rain Animation Studios, the first of its kind in Kathmandu. Initially, the company focused on animating films for Hollywood. But in 2010, when a 7.0 magnitude earthquake levelled Port-au-Prince, Haiti, Joshi realised there was important work to be done about Nepal, which sits on a seismic fault line.

The UN, Red Cross and other development agencies poured money and resources into Nepal to raise awareness about disaster preparation and rescue procedures. But Joshi didn't think the message was reaching everyone.

So he teamed with the Red Cross and the US embassy to produce a series of animated public service announcements. In the videos, a red panda - a local animal - teaches people how to prepare for an earthquake as well as what to do during and after a disaster.

In January, Joshi debuted a different project: a documentary called . The film featured interviews with the few remaining survivors from Nepal's last devastating earthquake, an 8.2 magnitude tremor on January 15, 1934. More than 10,000 people died in Nepal, mostly in Kathmandu.

But Joshi wanted to do more than remind the Nepalese of the previous quake. He wanted to stir them to act to prevent another disaster. ("Their past could become our future" is the movie's tagline.) So he and his animators created dramatic scenes of the potential ruin another powerful quake could cause modern-day Kathmandu. "We destroyed many of Kathmandu's most famous monuments, including the Dharahara Tower, our No1 monument," he says. "In our documentary we levelled that off. We were trying to say, 'This is how bad the devastation could be.'"

They had debated long and hard about just how graphic to make the scenes in the movie, he says. "To what level do we portray those visuals? On one level you don't want people to panic, but on another level you want to wake them up. If you show just a few houses getting knocked down, people won't care unless it is their house. But if you are showing some significant landmarks of the country, it will send a very strong message."

Joshi's digitally animated film didn't prepare him for the destruction Kathmandu suffered on April 26, however. "That was the most devastating part - when I saw the news and I saw that the tower was completely knocked off."

Joshi managed to contact several of his co-workers in Kathmandu. None of his employees was seriously injured in the earthquake, but large cracks appeared in the office walls.

"We were very lucky," he says. "One artist comes from the epicentre area. He said his whole village is pretty much levelled off.

"It's very sad. I think Nepal and Kathmandu will never be what they were before. Besides losing so many lives [at least 7,500 dead], lots of our culture is in our buildings and monuments. They are completely damaged.

"What I love about Nepal is its rich culture. Every one of those temples and monuments has a history why they were built. I know they will build back the city, but some of the charm about these old antique buildings will be gone."

From 1996 until 2006, Nepal was gripped by conflicts between government forces and Maoist insurgents. Since then, political squabbling has often stymied progress. Joshi hopes the solidarity he has seen since the earthquake will push the poor, Himalayan country past such problems.

He says he can't be sure his public service announcements or even his apocalyptic movie helped save any lives, but his movies might be able to play a role in rebuilding Kathmandu by reminding people of what has been lost.