The US has some of the most dangerous cities in the world: Detroit and New Orleans.

How did it get to this point? Is there anything we can do about it? What about the other cities? What are the common factors?

http://www.vancouversun.com/news/Detroit+most+dangerous+cities+planet/2914738/story.html

Detroit one of the most dangerous cities on the planet: CNN
By Star StaffApril 16, 2010 12:04 PM

WINDSOR, Ont. — Detroit has been named one of the most dangerous cities on the planet in a survey cobbled together by CNN. Joining Detroit on the dubious list are such tourist hotspots as Bagdad, Karachi, Pakistan, Beirut and Kinshasa in the Democratic Republic of Congo.
The list was cobbled together as part of CNN's Urban Planet series and is based on data from Mercer's global report on personal safety and Foreign Policy magazine's most recent report on murder rates. The list is also based on data from Forbes and the Citizen's Council for Public Security.
The full list of cities includes Detroit; New Orleans; Juarez, Mexico; Karachi, Pakistan; Caracas, Venezuela; Cape Town, South Africa; Moscow, Russia and Kinshasa in the Democratic Repubic of Congo.