A mysterious set of medical complications plagues some survivors: joint pain, vision loss, rashes. Doctors aren't sure why it's all happening. But they have a name for it: Post-Ebola syndrome.
Thirteen-year-old Nicholas Heyward Jr. was playing with a toy gun in the stairwell of the housing complex where he lived in Brooklyn when a police officer shot and killed him in 1994.
New charities pop up all the time. But how do you know which ones work? Economists have come up with a strategy to figure it out. They've used it to tackle one of the biggest problems in the world.