Stanley Charles Preston, in his 99th year, passed away on May 15, 2019 at Sunnybrook Veterans Centre in Toronto. Stan was born in Toronto to the late Lillian (Thompson) and Stanley Charles Preston. Stan served in WWII in the RCAF as a wireless operator air gunner and Warrant Officer II (1941-1945) and after the war, completed grades 9 to 13 in a space of 6 months and then went to the University of Toronto through the Veterans Charter, graduating in Engineering Physics. In 1950, Stan prepared electrical specifications at his kitchen table for the development of the first external electronic cardiac pacemaker-defibrillator by Dr. Wilfred Bigelow and Dr. John Callaghan of the Banting and Best Institute of the University of Toronto in conjunction with Dr. John Hopps of the National Research Council of Canada. Stan worked as a Professional Engineer with the Ontario Hydro (now the OPG) for 32 years, during which time he designed power plants. He had great humour and generosity, and loved spending time with children. He was the beloved husband of the late Doris Lillian (Sidney) Preston for 69 years. He was the dear father of Lorne Preston (Dorie) of Toronto, Larry Preston (deceased), Marianne Moore (Cliff) of Ottawa, Janet Preston of Toronto, Susan Falls (Larry, deceased) of Oakville, Robert Preston (Janice) of Penetanguishene, and Cynthia Preston (Shawn Theriault). Greatly missed by 17 grandchildren, 2 step-grandchildren, and 31 great-grandchildren with more on the way. Survived by his sister Muriel Nickerson. Predeceased by siblings Margaret, Audrey, Helen (Miller), Harold, Russell, Ken, Reg, Cliff, Merle (Whibley), and Fred. Stan will be greatly missed by his large extended family and friends. Internment to take place at Park Lawn Cemetery in a private family ceremony. Those who wish to remember Stan in a special way may make gifts in his memory to The Salvation Army, The War Amps, and The Scott Mission. His family wishes to extend their thanks and gratitude to the wonderful staff at Sunnybrook Veterans Centre, L Wing.