Phong Diep

Phong Diep, PhD, 53, of Ithaca, NY passed away unexpectedly on April 25, 2026.

Born on November 20, 1972, in Saigon, Vietnam, Phong was the beloved son of Ha T. Diep and Ngan T. Diep (Ly). With the assistance of the First Presbyterian Church of Baldwinsville, Phong and his family settled in Baldwinsville, NY in 1980.

Phong graduated as his class Valedictorian from Charles W. Baker High School in 1991 and went on to earn his bachelor’s in chemical engineering from Cornell University in 1995. He completed his formal education with a PhD in Chemical Engineering from the University of Pittsburgh in 2000. In June 2000 he started a very distinguished 26-year career with Corning Incorporated. He was the Director of Modeling & Computing Technologies at Corning Incorporated at the time of his passing.

He met his husband, Brian J. Smith, in 2004 and together they built a very good life rooted in love, partnership and community in Ithaca. Phong and Brian have been married since 2014. He was a deeply compassionate person whose warm, welcoming smile made others feel instantly at ease. He carried a quiet sense of positivity and calm, even during life’s more difficult moments, whether at work or at home. He had an unwavering dedication to developing people and empowering others and left an indelible mark on Corning’s Technology Community. He championed the role of supervisor and manager and invested in creating an environment of learning and support for managers that he trained. During the 2026 Spring Term, Phong had been acting as a liaison for Corning Incorporated with Cornell’s DNCB Project at the R.F. Smith School of Chemical and Biomolecular Engineering to provide students with experiential-based learning opportunities.

He loved his family and friends wholeheartedly, and they knew they could always turn to him - for advice, a listening ear, for comfort, or simply for the steady presence he offered so generously. His love for life shone through in the things that brought him joy - music, entertaining, cooking, cars, watches, fountain pens and the arts - and he shared that joy freely with those around him. Phong enriched the lives of those lucky enough to cross his path. His passing leaves a profound and tender space in the hearts of all who knew him, one that will not be easily filled. He was passionate about supporting others and contributing to causes that foster inclusion and well-being. Phong was a Member of the Board of Directors of Family & Children’s Services from 2022 through 2025 of Ithaca, and a member of Corning Incorporated’s employee resource group for LGBTQ+ employees (SPECTRA). He helped found the Finger Lakes LGBT Workplace Alliance - an organization consisting of several LGBT ERGs from the Rochester and Finger Lakes area, serving as Corning’s representative for several years.

He was preceded in death by his father Ha T. Diep; his aunt Quyen Chau; his uncle An Ly; his uncle Lac Ly; mother-in-law Lorraine A. Smith; father-in-law John R. Smith, Sr.; sister-in-law Mary Jane Aikens; and brothers-in-law Patrick A. Smith and John R. Smith, Jr; and his Jack Russell Terrier, Macy.

Phong is survived by his husband, Brian J. Smith of Ithaca, NY; his daughter, Meghann L. Smith of Baldwinsville, NY; his mother, Ngan T. Diep of Ithaca, NY; his brother and sister-in-law, Gia & Shannon Diep and nieces and nephew Madelyn, Justin & Emily Diep of Baldwinsville, NY; sisters-in-law Sharon A. Smith and Abby Brown of Rome, NY, Jacqueline Libertino of Fredericksburg, VA, Kathryn Tuthill of Lee, NY, Lorraine Cimpi (Dave) of Oneida, NY, Tricia Hladun (Richard) of Holland Patent, NY and brothers-in law Michael Smith (Judy) of Rome and Richard Smith (Maryann) of Oneida, as well as his extended family, including Aunts and Uncles Tuong Ly (Nhi) of Voorhees, NJ; Linh Ly of Boston, MA; Hung Chau of Toronto, Ontario; Kaen Diep (San) of Somerville, MA; Quoc Diep (Muoi) of West Hartford, CT; Quang Diep (Nhi) of Toronto, Ontario; Vinh Diep of Voorhees, NJ; and Dinh Tran (Ha); cousins Jason Chau (Jenny), Ellen Hermance (Jarrod), George Diep (Dianne), Kevin Diep (Jeannine), Allie Diep (Brian), Diana Diep, Philip Tran (Jackie), Donald Tran (Emily), Tiffany Diep, Sally Patel (Akshar), Aaron Diep (Anna) and Michelle Ly. He is also survived by his beloved Boston Terrier, Sofi, who brought joy and companionship to his life.

A memorial service will be held on May 9th at 2:00 p.m. at The Statler Hotel in Ithaca, NY. The family will share additional service details.

In lieu of flowers, the family kindly requests that donations be made to The SPCA of Tompkins County.