Britain's black economy draws Vietnamese migrants.

The deaths of 39 migrants in the back of a refrigerated truck near London last week has focused a spotlight on the lives of those who risk everything to earn a better living in Britain.

Many of the victims are believed to have traveled from Vietnam. Tamsin Barber, an expert on the Vietnamese diaspora in Britain at Oxford Brookes University, says many migrants are willing to take huge risks.

"They're doing that because they know that when they get to the UK, the likelihood is that they're...