Why is life expectancy in Sierra Leone 40 years?

There is no more vivid example of the extremes of life than with the subject of death.

As part of the BBC's Extreme World series, our correspondent Mark Doyle has been to one of the poorest countries in the world, where life expectancy is just 40 years.

A country where pain relief for those nearing the end of their life is in short supply.

The country is Sierra Leone and Mark reports from the capital Freetown.