There's a crazy story floating on the social media sites about a boy in India dying because his cell phone blew up. First of all, this is essentially the new form of chain letter; people only read the headline, see the picture, and fill in the facts on their own, then pass it along.
Second, this story has just enough truth to make it believable. A phone did explode in India, a boy did get injured...but he didn't die, and it wasn't because his cell phone was plugged in while he used it.
Here's the deal, the boy was using a bootleg, fake, Chinese knock-off phone. These products are held to no safety standards, have no inspection requirements, and are flat out dangerous. If you're using a knock-off phone, you may have an issue to worry about. But if you're using an actual iPhone, Samsung, LG, or other respectable brand, you don't have much worry. There's always the possibility of some malfunction, but not to this level.
Oh, and even though the poor boy did suffer injuries, he didn't die. You can actually read a full break-down on this hoax here: http://www.hoax-slayer.com/boy-died-mumbai-phone-call-while-charging.shtml