11 climbers appeared to have died on the world's second highest mountain K2.

It was one of the deadliest days in mountaineering history.

Rock falls, avalanches.

Huge pieces of ice.

All are big enough to kill you.

He just flew out into Devoid, and he was gone.

How did it all go so wrong?

And is it really worth risking death to feel alive? Why would

somebody pay to go to a place called the death zone on vacation? Extreme, peak danger. With me,

Natalia Melman Petrazella. Listen to the full series now. First on BBC Sounds. You're listening to a

program from BBC Radio 4.

I've come to a place today that I've never been before and I love to do something new.

I'm standing on a metal bridge at Rainer Marshes looking across at the Thames.

I'm looking just with my eyes.

Sam West, who I'm with, has immediately got his binoculars

up to his eyes because he is a mad keen birder. And I say burder advisedly because you're not a

twitcher, you are a birder and there is a difference. There is and a lot of people use them

interchangeably and I'm a bit of both, but there's a sort of sliding scale of geekiness that goes from putting food out for the birds

and being a bird watcher, and then taking it a bit more seriously,

not just watching them, listening, withdrawing them, writing about them.

And those people call themselves birders.

And then there's twitching, which is a kind of subset of birding,

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