A Champaign, Illinois, teen’s death is under investigation after he mysteriously died on Saturday. The News-Gazette reports that Luke Miller, a 15-year-old high school student at Centennial High School, went to the Carle Hospital Emergency Department just after 8:30 p.m.  A short while after, he was airlifted to Barnes Hospital in St. Louis. By 10:05 p.m. he …