This morning my son unplugged an I phone charger from an outlet in his room, there was a loud pop and sparks. The face of the charger and the outlet are blackened and the charger even looks a bit melted. It did not trip the breaker and I still show power to both plugs. He was using the charger brick for his USB powered headphones, I'm not sure that makes a difference. Do you think it's the charger or the outlet? The outlet is less than two years old and the house was built in the late seventies or early eighties. I'm assuming I should replace the outlet but I'm a bit worried that I don't really know what happened. Any input is greatly appreciated. Thanks, Joe.