On Saturday, Reelz aired Autopsy: The Last Hours ofCory Monteith, which explained the circumstances surrounding the 31-year-old Glee actor's untimely passing. However, learning the details of Monteith's death is no consolation — instead, it's a reminder of how incredibly sad his story is.Monteith's death was not only tragic, but shocking, as well. The TV star, who played the clean-cut football player Finn on the Fox series, was found dead in his Vancouver, Canada, hotel room on July 13, 2013. In the months leading up to his death, Monteith, who had battled drug and alcohol problems since his early teens, spent some time in rehab . Now, the new Reelz special suggests it was this time of abstinence that ultimately caused Monteith's sudden death. Dr. Michael Hunter , a world-renowned forensic pathologist, takes viewers through a detailed examination of the circumstances surrounding Monteith's death. First, he talks about why Monteith's death was particularly odd — the actor was seemingly healthy, fit, and happy prior to his death. Hunter is able to rule out congenital heart failure, as well as alcohol poisoning. However, when studying Monteith's battle with drugs and alcohol in combination with his post-mortem toxicology report, it becomes clear that something is amiss.Ultimately, Hunter concludes that Monteith's death had to do with a combination of alcohol and heroin. In addition to alcohol suppressing his central nervous system and acting with the depressant effects of heroin, Hunter states it was Monteith's time of abstinence that made the amount of heroin he used fatal.Despite a few painful reenactment sequences that showcased Monteith's drug spiral, I found the Reelz special particularly illuminating. It shows the upward battle people suffering with addiction must fight on a daily basis, no matter how famous or beloved they are. Just one week before Monteith's death, he had attended an AA meeting. His friends and family stated that they rarely (if ever) saw him drink in the years before his death. It's clear that Monteith was able to manage his addiction for years, and that, tragically, one night off the wagon led to his death.