The shocking death of American Idol finalist Michael Johns left his family, friends and fans reeling - and left many wondering about what caused it. According to various reports, the Australian singer, 35, died Friday from a blood clot originating in his ankle. But how did something so routine turn fatal? According to internist Dr. Levi Benson, "very few" blood clots turn out to be deadly. "The huge majority of people who get a blood clot do fine," he says. "A medical professional can prescribe blood thinners, and the clots usually go away in a few months." Clots, which are also...