Michael D. "Big Mac" McCormack, 72, of Natrona Heights, passed away Thursday, Dec. 27, 2018, at Allegheny Valley Hospital Harrison Township. He was born June 6, 1946, in Harrison Township, and lived in the area all of his life. He graduated from California State University with a degree in education. He was a teacher who taught earth science for 32 years at Deer Lakes High School. He was the son of the late James McCormack and the late Dorothy Divins McCormack. He was a member of St. Barnabas Episcopal Church, Brackenridge, and was a eucharistic minister of the church and sang in the choir, He was a youth counselor for Calvary Camp and cut grass for years. He was a member of PSEA for 30 years with the Highland Hornets. He enjoyed watching TV and the Steelers, Pirates, sports and movies. He enjoyed traveling the world, doing word puzzles and word searches, and he was an amateur carpenter. He is survived by two sisters, Barbara Eisenhart (George), of Vestavia Hills, Ala., and Maureen Swierczewski, of New Kensington; brother, Kenneth James McCormack (Adele), Harrison Township; nieces and nephews, Lisa, Eric, David, Erin, Kimberly and Megan; and great-nieces and -nephews, Christian, Noah, Rhiannon, Joseph, Nicholas and David. He was preceded in death by parents, James and Dorothy Divins McCormack; and brother-in-law, Gerald Swierczewski. "Big Mac," as he was lovingly known, was a kind and gentle man who gave of himself to everyone. No one ever had a mean comment to say about him and he was always a jokester with a smile. Family will receive friends from 2 to 4 and 6 to 8 p.m. Wednesday, Jan. 2, 2019, in the KRYNICKI FUNERAL HOME INC., 1007 Freeport Road, Natrona Heights. Services will be held at 1 p.m. Thursday, Jan. 3, 2019, at St. Barnabas Episcopal Church, 989 Morgan St., Brackenridge, PA 15014, with the Rev. Chip Koehler officiating. Interment will be in Mt. Airy Cemetery, Harrison Township. Online Condolences maybe made at www.krynickifh.com.