Mark Deetjen, devoted husband, father, grandfather, entrepreneur, philanthropist, and friend, passed away on September 28, 2025, surrounded by his loving family. Born on March 6, 1965, in Naperville, Illinois, to Don and Mary Deetjen, Mark lived a life full of energy, generosity, and vision—always finding room for laughter along the way.

Mark grew up in Naperville, attending Naperville Central High School before graduating from St. John's Military Academy. He earned his engineering degree from Northern Illinois University, where he also met the love of his life, Karla who became his partner in everything—family, business, and countless adventures.

A second-generation member of the construction industry, Mark began his career working for his father's companies in Chicago. In 1994, he joined his Uncle, Jim Deetjen, to create Premium Concrete, which went on to become one of the top concrete contractors in the Chicagoland area. He later launched Premium Electric Services and expanded into general construction and management with PCS Building Corporation in the mid 2000s, and in 2019 established Premium West in San Diego, where he proudly served as founder and President. His sons and son-in-law joined the company over the last 10 years and Mark was so proud of being able to work side by side with family.  His children now carry forward his vision, with Tyler leading Premium West and Bradley Premium Concrete.

As proud as Mark was of his businesses, nothing compared to his family.  He is survived by his beloved wife Karla Deetjen; his children Tyler (Marie) Deetjen, Bradley (Alda) Deetjen, and Janelle (Alec) Fitzsimons; and six grandchildren who brought him endless joy: Tyler, Marisel, Greyson, Kensley, Isla, and Marcos.

Mark's generosity was extraordinary. He gave freely of his time, talents, and resources to support charitable causes in San Diego, St. Charles, Naperville, and Chicago. Just as importantly, his support of friends was legendary—he was always the one to show up, lend a hand, or share a laugh. And when it came to gatherings, Mark had a way of lighting up every room. He was the life of every party he attended—even a few he wasn't invited to.

Those who knew Mark will remember his sharp mind, boundless energy, and big heart. He loved building—whether it was companies, relationships, or communities—and he inspired loyalty and friendship wherever he went. His indestructible determination, strength and faith are words anyone who met Mark used to describe him. His life reminds us that true success is measured not only in business accomplishments, but in love shared, families raised, communities strengthened, and joy spread.

Services are planned for both San Diego, California and St. Charles, Illinois. Visitation Wednesday, October 8th from 4-8PM at the Church of the Nativity 6309 El Apajo, Rancho Santa Fe, California. Funeral Mass will be held on Thursday October 9th.  at 11:00 AM at the Church of the Nativity with eulogy prior to Mass. Burial to follow at El Camino Memorial 5600 Carroll Canyon Rd, San Diego, California. The day will end with a celebration at one of Mark's most cherished restaurants, Lana at 437 S Hwy 101 in Solana Beach. The Chicago gathering in honor of Mark will be Sunday, November 16th including Sunday Mass at 11AM at St. John Neumann located at 2900 E Main St, St. Charles, Illinois 60174, followed by a luncheon at 1PM at Royal Fox Country Club located at 4405 Royal and Ancient Dr, St. Charles, Illinois.

In lieu of flowers, we ask you to make a donation to the charity of your choice. Mark enjoyed spreading his impact and would be happy if you did the same. Mark leaves behind a remarkable legacy of love, laughter, generosity, and determination that will continue to inspire all who knew him.