Donald Jankowski "Don" Passed away at the age of 87 on Sunday, February 14, 2021 at his late residence. Don was born in Chicago Heights, Il on October 11, 1933 and was blessed to be a part of two loving marriages, both spanning over twenty-five years. He served proudly in the Air Force during the Korean War. Don took great pride working over forty years as a scientific associate at Argonne National Laboratory in Lemont. Don was part of the proton decay project in Soudan, MN, the twelve-foot deuterium bubble chamber project in Lemont, plus other experiments using the ZGS accelerator. Don also oversaw Argonne's safety program for the high energy physics' division. At home, Don often could be found working in the garden or fishing with his family. He dedicated himself to serving his family well and desired to make sure his children were given a solid foundation to make a difference in the lives they chose to lead. Don and Maria are most indebted to those who provided wonderful care while fighting his battle with cancer. "To maintain a joyful family requires much from both the parents and the children. Each member of the family has to become, in a special way, the servant of the others." - St. Pope John Paul II. He was preceded in death by his loving first wife, Zaira Zelinda Jankowski, his parents, Benjamin and Henrietta Jankowski and his siblings, John and Dolores Jankowski. Donald is survived by his loving wife, Maria (nee Supinski) Jankowski; his beloved children, Linda, Michael, Benjamin (Marline), Rev. Peter and Julian Jankowski; his brother, Richard (Helen) Jankowski; sister-in-law, Patricia Jankowski and grandchildren, Grace and Naomi Jankowski; many nieces, nephews and cousins also survive. Visitation for Donald Jankowski will be held at the Carlson-Holmquist-Sayles Funeral Home and Crematory, 2320 Black Road, Joliet on Thursday, February 18, 2021 from 3:00 pm to 8:00 pm. A Mass of Christian Burial will be celebrated at St. Joseph's Catholic Church, 416 N. Chicago St. Joliet on Friday, February 19, 2021 at 10:00 am. Per Donald's wishes, cremation rites will be accorded following the mass. A Memorial Mass of Christian Burial will then be celebrated at St. Paul the Apostle Catholic Church, 340 West Arnold Street, Sandwich, IL on Friday, February 26, 2021 at 11:00 am. Inurnment will follow the mass at St. Paul Cemetery, Sandwich. In accordance with CDC Covid Guidelines, everyone attending the visitation and funeral services will be required to properly wear a facial mask and observe social distancing. Due to attendance restrictions and in order to attend the funeral mass at either church, you are required to register your name and contact information by calling the funeral home prior to the day of service at (815) 744-0022. Memorials in Donald's memory to the donor's choice would be appreciated.