John "Jack" Armstrong, age 86, of Duluth, passed away on January 2, 2016, while surrounded by family at Chris Jensen Rehabilitation Center. He was born on March 16, 1929, to Al and Minnie Grunwald. He grew up in Gordon, WI. He entered the United States Army and served in the Korean War. On January 18, 1969, John was united in marriage with Margaret Jenson in Duluth. John worked for the City of Duluth as a zookeeper at the Lake Superior Zoo. He enjoyed hunting and spending time with his children John and Dennis.   Jack is preceded in death by his parents; and son, John Armstrong Jr. Jack is survived by his wife, Margaret; son, Dennis; and sisters, Ginger and MaryLou. A funeral service will be held on January 5th, 2016, at Zion Church at 11:00 AM with Pastor Judy Anderson-Bauer officiating. Visitation will be one hour prior to the service. Burial will follow the service at Sunrise Cemetery.