DeBORTOLI

ROSEMARY THERESA

Rosemary Theresa DeBortoli, a resident of Mount Lebanon, died on Tuesday, January 13, 2026, of complications following a stroke. She was 98 years old.

Rosemary, known to her family and friends as Pooch, was born on April 18, 1927, in Ellwood City, Pennsylvania, the third child and only daughter of Mark Joseph DeBortoli (1896-1978) and Rose Elizabeth (Falconie) DeBortoli (1896-1952). Her father was a steelworker and later a foreman in the seamless tube mills of the National Tube division of U.S. Steel.

Rosemary grew up in Ellwood City and graduated from Lincoln High School in 1945 while her older brothers were serving in the Army in the European Theater of Operations of World War II. She attended Duquesne University for one year and graduated from the Carnegie Institute of Technology with a bachelor's degree in general science in 1950. In 1973, she obtained a master's degree in library science from the University of Pittsburgh.

Beginning in 1951, Rosemary worked as a chemist in the tar products division of Koppers Company for 17 years, and then for 24 years in the chemicals division of U.S. Steel on Neville Island, which was sold to Aristech Chemical. She retired in 1992, but maintained a lifelong interest in science and technology, keeping up-to-date on advancements via her iPad into her late 90s. She was a devoted member of the Ciloets (pronounced "silhouettes"), a U.S. Steel organization that furthered the interests and knowledge of women employees during their careers and into retirement.

Rosemary was a fiercely independent woman who lived her nearly 99 years to the fullest. She was ahead of her time in her professional career in a field with few women. She relished debating politics and current events with her grandnieces and grandnephews and had a passion for history - particularly World War II, in light of her brothers' service. Rosemary was a connoisseur of fine wine, and she proudly contributed her homemade Manhattan cocktails to every family occasion.

Rosemary continued to learn throughout her life, taking an interest in cooking and nutrition, finances and investment, and acquiring the latest kitchen gadgets and computing devices. During her retirement, she cultivated a particular interest in art and Impressionist painting, visiting museum exhibits around the country, and enjoyed many travel adventures throughout Europe with family and friends, visiting such sights as Monet's house and gardens at Giverny and Renoir's gardens. She also enjoyed traveling with family, including beloved trips to Maine for over 25 years, where she indulged in many fine lobster dinners, as well as time spent avoiding the sun at Wrightsville Beach, North Carolina. Her family will particularly remember her hand-drawn birthday greetings from World War I Flying Ace Snoopy on his doghouse "flying by to say hi" and her "toodle-oo" that ended each phone call or get-together.

Rosemary was preceded in death by her parents; her brother and sister-in law, Mark and Dorothy DeBortoli; and her brother, Robert DeBortoli. She is survived by her sister-in-law, Annamarie DeBortoli, of Bethel Park; her nephew, Mark DeBortoli (Julie), of Clifton Park, New York, and his children, Robert (Ariel), Mitchell, and Olivia, and grandson, Theodore; her niece, Elizabeth Schierling (John), of Clifton, Virginia, and her children, Mark, Jeanne Marie, Jack, Marianne, and Peter; and her niece, Michelle Djuric (Nikola), of Atlanta, Georgia, and her children, Madeleine, Henry, and Joseph.

A Mass of Christian Burial will be held at 10:00 a.m. on Saturday, January 17, at St. Michael the Archangel Parish - St. Bernard Church, followed by burial at Holy Redeemer Cemetery/Saint Agatha Cemetery in Ellwood City. In lieu of flowers, contributions may be made to an organization of your choice benefiting veterans.