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. My guest today is

probably the world's most famous college dropout. Of course,

there've been other monikas over the years, computing pioneer, richest man in the world, global

philanthropist, even tech supervillain. Whatever your take on Bill Gates, after years at the

corporate Colface, building a software empire and a vast fortune, his priority now is

giving that away. And his ethos for doing it has been shaped by his international experiences and

by science. Famed for co-founding the software company Microsoft, for the past 25 years, Bill's

attention has been focused on philanthropic efforts via the Gates Foundation,

one of the largest charities in the world. There, Bill and his billions have taken on issues

around health, inequality, education and climate change in some of the world's poorest countries.

And their impact has been undeniable, from helping eradicate wild poliovirus in Africa,

to supporting efforts,

which over the past 25 years have more than halved global child mortality rates. Bill says none of this work is easily accomplished, but most goals worth achieving aren't. And as I suspect,

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