Louis Roger LaDouceur Jr. passed away on September 26, 2026 in Richland, at the age of 97. Born in Vancouver, Washington on November 2, 1928. Married Helen Beames Wanner on February 2,1969. Lou was a long-time resident who lived in the Tri-Cities area for over 70 years.

Lou was drafted into the army during the Korean War, where he proudly served. Following his military service, he attended Washington State University, graduating in 1957 with a Bachelors in Architectural Engineering. Throughout his life, he remained a big supporter of WSU athletics.

Lou's extensive career left a major architectural footprint on the region. His work at the Hanford Site began in 1957 when he was hired on the spot after walking into the human resources building. Over the next 35 years, he designed and modified hundreds of buildings for Hanford. Alongside his manager John Waite, Lou completed the architectural design for the historic N-Reactor, and he later noted that he had touched every one of the site's reactors in some capacity. His other notable designs included the large domed Plutonium Recycle Test Reactor and the High-Temperature Lattice Reactor.

Though Lou officially retired in 1989, he continued to lend his expertise to the nuclear field as a consultant and temporary employee for various contractors. In 2001, he joined Bechtel full-time to work on the Waste Treatment Plant (WTP). He served as the lead architect for the Pretreatment Facility, Low-Activity Waste Facility, and Analytical Laboratory, eventually transitioning into a role as a lead coordinator where he mentored a younger generation of WTP architects.

Outside of his professional life, Lou was an avid outdoorsman who loved fishing, as well as duck and elk hunting. He was a proud member of the Richland Rod and Gun Club and the VFW. His favorite traditions included yearly fishing trips to Twin Lakes and the annual elk hunting trip on White Pass. He also cherished the countless cold morning boat trips out onto the 4th Island for duck hunting alongside his son and favorite son-in-law and grandson.

Lou is survived by his beloved wife, Helen; his son, Brett; and his stepchildren, Scott and Linda. Arrangements are under the care of Mueller's Tri-Cities Funeral Home in Kennewick.