Dr. Patrick J. Pagni, professor, scholar, and consultant passed away peacefully on February 1, 2026, at the age of 83.

Born in Chicago, Illinois, Professor Patrick Pagni earned a Ph.D. in Mechanical Engineering from the Massachusetts Institute of Technology and went on to teach at the University of California, Berkeley, for more than 30 years. An expert in fire science, he was widely respected for his research and scholarship in combustion with emphasis on fire development. He was an excellent teacher and had the talent of explaining complex concepts in simple terms. This talent helped him to develop a very successful consulting career in fire litigation.

Throughout his career at U.C. Berkeley, Professor Pagni conducted pioneering fundamental research on a number of fire related problems that brought further understanding of the mechanisms controlling fire. Early on he studied smoke production from burning solid combustible materials and introduced the concept of “excess pyrolyzate” to describe unburned pyrolysis products. He showed that excess pyrolyzate has a determining role in the length of diffusion flames from burning solids. He also contributed to the theoretical modeling of smolder in porous materials, and of flame spread over solid and porous fuel beds. After the catastrophic fire in the Oakland Hills of 1991, he became interested in the modeling of wildland fire propagation, and the contribution of ember spotting on the rapid spread and hazards of wildland fires. Working with his graduate students he developed a numerical model of wildland fire propagation by ember spotting that is often referred to. His contribution to the fire community was not limited to his research, but also to the dissemination of fire as a societal problem. This was done through his leadership role in the International Association for Fire Safety Science (IAFSS): Professor Pagni was one of the founders of the IAFSS as a member of the first Organizing Committee in 1985; he was a member of the Executive Committee and Management Committee of the IAFSS for most of the 1990s and 2000s; he was also awarded the Howard W. Emmons Invited Plenary Lectureship in 2002 (one of the two most prestigious IAFSS Awards). In addition, during the 1980s and 1990s, Professor Pagni played a leading role in a collaboration on fire research between the National Institute of Standards and Technology (NIST) in the US and the Building Research Institute (BRI) in Japan.

At U.C. Berkeley Professor Pagni taught courses in the Department of Mechanical Engineering, including Thermodynamics, Heat Transfer and Combustion. He also developed a particularly interesting course on the application of the fundamentals of fire to analyze actual fires, such as the Oakland Hills wildland fire, among others. He was very dedicated to his teaching, preparing well organized and clear lectures that the students loved. He also mentored young colleagues, and numerous graduate students, interacting and working with them on a variety of fire-related subjects.

Beyond academia, Professor Pagni enjoyed collecting old maps and coins from around the world, some of them quite rare. He loved good food and wine and enjoyed explaining to his guests the origin of the wines. His wine testing reunions with bottles with no labels were quite fun, and often with surprising results.

He is survived by his wife, children and grandchildren; and a wide circle of colleagues, former students, and friends who will continue to carry his lessons and friendship forward.

A. Carlos Fernandez-Pello (University of California Berkeley, Berkeley CA, USA)