(Newser) – The last message sent by 14-year-old Madison Coe before she was electrocuted in the bathtub shows the tragic mistake that killed her. "When you use and (sic) extension cord so you can plug your phone in while you're in the bath," the teen from Lovington, NM, wrote to a friend, sending a picture of the cord connection on top of a towel. But despite the precautions, Madison was apparently unaware that there was fraying on part of the cord, NBC 12 reports. Officials say she was killed after touching a frayed section while she was in the water....