This is the BBC.

Hello, I'm Lucy Ash and you're listening to assignment on the BBC World Service.

This week I'm in Russia to investigate a very strange and very risky new trend.

In a town in Siberia a young man straps a camera on his head as he teeters on the edge of the roof of a nine-story apartment block.

I'm a legend he declared. of a nine-story apartment block.

I'm a legend, he declares, as a friend hands him a flaming torch

which he uses to set fire to his trousers.

Orange flames quickly snake up his legs and suddenly he jumps.

And lands with a thud into a deep pile of snow, winded from his fall he groans as friends rush up to him.

Good lad, they say proudly, well done, and a small crowd applauds.

Astonishingly, he seems unharmed. Within hours footage of the jump went viral and

like millions of other people around the world I watched the video with horror and

disbelief. What could have possessed this man to do such a thing?

So I bordered a plane for a remote part of southwest Siberia to find out more about

Russia's internet daredevils.

There's a watery sun in the sky.

The temperatures minus 18.

I can't feel my fingers anymore. I'm in Novo Al-Taysk, which is a small town in southern

Siberia, and right at the moment I'm standing underneath an apartment block.

It's a difficult Soviet type block with concrete slabs and rusty iron balconies.

And there's one, two, three, four, five, six, seven, eight, nine.

Yeah, there are nine floors.

...