John G. "Jack" Rock III, 81, of Upper Chichester passed away peacefully on Monday, November 24, 2025, at Riddle Hospital, Media, Pennsylvania.

Jack was born and raised in Springfield, Pennsylvania and was a 1962 graduate of Springfield High School.

Jack honorably served our nation in the United States Marine Corps reserves and started his professional career in the Automotive field specializing in repairs. Using the knowledge he gained early on in life, he ultimately established a career at Boeing working as an engineering manager.

Jack enjoyed both bowling and skeet shooting. He also served as a motorcycle instructor for over thirty years, teaching courses in Pennsylvania. Additionally, he served as an EMT for many years, teaching classes at Delaware Community College and also volunteered at the Boothwyn Fire Department. He was previously a member of Springfield Presbyterian Church.

He is preceded in death by his parents: John G. Rock II, and Ruth Cora LeCates.

Survivors: his beloved wife: Leona Sigurdson, stepchildren: Mark Daniel (Maria) and Dawn Shirron (Paul), and grandchildren: Jason, Nick (Rachael), Tattiana, and Luca, and great-grandchildren: Aubrianna and Landen.

Funeral services will be private and at the convenience of the family.

In lieu of flowers memorial contributions can be made in Jack's honor to Doctors without Borders .