Detlef W. Detjen, a World War II veteran who was an integral member of Berglund Construction for more than half a century, died on July 21. He was 94.

Mr. Detjen was a 15-year-old gas station attendant when he serviced the car of a man named Fred Berglund, the founder and president of what was then known as the Berglund Maintenance Company. Impressed by the young man, Mr. Berglund offered him a job at his company before pulling out of the gas station. Mr. Detjen immediately accepted the offer and went to work as a laborer.

A strong man who was known for lifting heavy material and equipment in the field, Mr. Detjen performed some of the company’s most difficult jobs and quickly gained the trust of Mr. Berglund, who often brought him along to his jobsite visits. Mr. Detjen then paused his work at the company to serve as a member of the United States Air Force in World War II, for which he became a five battle star recipient.

Upon returning to work, Mr. Detjen became close with Mr. Berglund’s two sons who were of similar age and ascending in the company: Roger, who also served in World War II, and Norman. The three of them worked together to grow the company, which included adding new construction and interior remodeling services under the name Fred Berglund & Sons, Inc.

Mr. Detjen had several important and versatile skills that were integral to the company’s success. An outstanding estimator and project manager, he had a knack for developing, growing and maintaining client relations, which allowed him to maintain several important long-term accounts during his career. From his start as a 15-year-old laborer, he worked his way to becoming a top executive when he was named senior vice president. His tenure included seeing his sons Mark and Craig spend time working at the company, and he retired after more than 50 years with Berglund.

Mr. Detjen’s career included serving as a mentor to the third generation of Berglund leadership. Fred Berglund, the current president and namesake of the man who met Mr. Detjen at a gas station nearly 80 years ago, is grateful to have worked alongside him.

“I had the opportunity to work with Detlef for over 20 years and was fortunate to learn a tremendous amount from him,” he said. “He played an instrumental role in the successful history of this company.”