Gilbert L. Duncan, 84, of Plainfield, passed away January 6, 2018. He was born January 15, 1933 to the late Lawrence and Ophia (Nauman) Duncan in Greencastle, IN. He was a US Coast Guard veteran. He was a member of the Plainfield Christian Church, the Plainfield Masonic Lodge #653, OES, and the Plainfield Elks. He worked as a structural engineer for Duke Energy for 44 years retiring in 1995. Gilbert is survived by his wife, Charlotte M. (Liston) Duncan; a son, David E. (Angela) Duncan; a daughter, Janell L. Duncan; and 4 grandchildren, Li Cai and Lian Haney and Lauren and Peyton Duncan. He was preceded in death by a daughter, Mitzi Duncan. Funeral services will be at 1:00 pm on Tuesday, January 9, 2018 in the Hampton-Gentry Funeral Home, Plainfield, where friends may call on Tuesday from 11:00 am until service time at 1:00 pm. Burial will be in Maple Hill Cemetery, Plainfield.