MINNEAPOLIS — The death of Adam Zimmer, a former Minnesota Vikings co-defensive coordinator and the son of former head coach Mike Zimmer, was caused by chronic alcohol use, according to medical examiners.The Hennepin County Medical Examiner’s Office in Minnesota released the finding Friday. Zimmer was found dead in his home in Mendota Heights, a Twin Cities suburb, on Oct. 31. He was 38.Adam Zimmer had been working remotely this season as an offensive analyst for the Cincinnati Bengals after eight years with the Vikings under his father. When Mike Zimmer was fired in January, the majority of his staff was also dismissed.Adam Zimmer broke into the NFL in 2006 with the New Orleans Saints. He was hired by the Kansas City Chiefs in 2010 as an assistant linebackers coach and spent the 2013 season with the Bengals as an assistant defensive backs coach in Mike Zimmer’s final season there as defensive coordinator.