>> Preparing for disaster, the UN busy at work just outside the Iraqi city of Mosul. It's preparing for a humanitarian crisis when the battle for the city begins. That, as Iraqi forces get ready to retake Islamic State's de facto capital in the country. The offensive expected to begin soon, and aid workers are worried.
>> Worst case scenario in Mosul would look something like this. You would have mass expulsion of hundreds of thousands of people.>> Right.>> You would have hundreds of thousands of people who are held as human shields inside the town.>> Right.>> You would have chemical attack that would put tens of thousands, hundreds of thousands, maybe even more, at grave risk.
If all of that were to happen at the same time, it would be a catastrophe.>> Mosul had a pre-war population of about 2 million. Now the UN's building what amounts to a new town for refugees. Accommodation, medical facility, food, and sanitation plants, all required. But the best laid plans might not be good enough.
>> If you were to see a forced population movement, more than 150,000 people, at that stage, there isn't an institution in the world that can cope with that scale of movement.>> Money a big problem. The UN says it could need a billion dollars to house all the refugees.
That's more than four times the amount pledged by international donors. So far, that money has paid for six camps that can house 50,000 people. 11 more such camps are planned. Even that may not be enough.