By Gina Martinezdeath of rapper Coolio was due to the effects of fentanyl, heroin and methamphetamines, his manager confirmed to CBS News.  The LA-based rapper was best known for his Grammy Award-winning single "Gangsta's Paradise," which was featured on the soundtrack for 1995's "Dangerous Minds" starring Michelle Pfeiffer.  The LA-based rapper was best known for his Grammy Award-winning single "Gangsta's Paradise," which was featured on the soundtrack for 1995's "Dangerous Minds" starring Michelle Pfeiffer