It has been two days now since a magnitude 7.0 earthquake shook the country's capital, Port-au-Prince, to its core. The Red Cross Federation now estimates the death toll at 45,000 to 50,000. For the tens of thousands of injured, many of the region's hospitals have been severely damaged — and outside medical and rescue groups are still struggling to reach the hardest-hit areas. Robert Siegel talks to NPR's Carrie Kahn, who is in Port-au-Prince, about the unfolding humanitarian crisis there.