Hello and welcome to NewsHour.
It's coming to you live from the BBC World Service Studios in central London.
I'm Tim Franks.
One of our jobs as journalists is to bear witness.
So when the path is blocked or when it's simply too dangerous to get somewhere,
that can be frustrating.
Think recently of Gaza or Myanmar.
Think now of Sudan, the site of the world's worst humanitarian catastrophe.
and reports of appalling atrocities, possibly genocidal in their scale,
in the west of the country, in Darfur,
as forces from the paramilitary RSF finally overran the city of El Fasha in their two-and-a-half-year-long war against the Sudanese National Army.
But when we can't be there ourselves, we can revisit the people and the incidents,
and we can hear from those caught in the maelstrom.
And so it may seem odd to start the program with an event which happened last month.
But our Africa correspondent, Barbara Pletasha,
has been doggedly gathering evidence of what the UN says was the mass killing of about 500 patients and staff at the Saudi hospital in El Fasha.
Mohammad Abdul Tia was in hospital the day Al-Fasher fell to paramilitary troops.
He'd been injured by shelling, yet even with a broken leg, he managed to flee the city on foot,
eventually making it to the town of Tawila, stopped by the RSF, but not detained, like many others.
They didn't beat me, but they questioned me a lot because of my injury, I think.