22-year old Brittany Prehn was attending the outdoor Country Thunder Music Festival in Wisconsin, and in the middle of a conversation on her smartphone, she was struck by lightning. Prehn was hit in the ear and the lightning traveled through the rest of her body. A medic at Northern Illinois Medical Center, where the victim was originally transported, noted that there was "significant damage to the phone" and all indications are that her handset was placed up to her ear as the lightning hit. But experts would say that there is no connection between the victim getting struck in the ear, and the fact that she was on a cellphone call at the time.
If you're worried about using your phone in the middle of a thunderstorm, which are quite common this time of the year in certain regions of the U.S., you have nothing to worry about. NOAA National Weather Service lightning expert John Jensenius says that "People are struck because they are in the wrong place at the wrong time. No lightning danger is inherent to cellular phones." So it would seem that Prehn was in the wrong place at the wrong time, and the fact that she was in the middle of a call when lightning struck was just bad luck.
In China, there are signs placed around the country warning people not to use their phone during lightning storms, but this would seem to be a misguided attempt to warn users of an issue that doesn't exist. Actually, there is more of a threat to your phone in a thunderstorm unless it has some form of water resistant coating or is rated high enough on the Ingress Protection (IP) scale. Phones rated IPX5 or higher have a better chance at surviving a downpour. Certain Motorola devices with nanocoating protection from P2i will make it through a light rain.
As for Brittany Prehn, she was transferred to Loyola University Medical Center where she is currently in the ICU unit.