William S. Mosich, 85, of San Juan Capistrano, CA, passed peacefully in his sleep on June 20, 2026. Known to many as Billy Mo, he was born to Joseph and Mary Mosich on November 12, 1940 in San Pedro, California.

Billy Mo will be forever known for his heart of gold—someone who treated others with great kindness and generosity. If you knew him, you loved him, and you know what a hole he leaves in our hearts. He had a way of telling it like it is, and his legacy will continue in the kindness he showed to others. He believed in treating people well and enjoyed finding ways to bring smiles to everyone around him. Whether it was commercial fishing in Alaska with cousins, enjoying Hawaii with family and friends, attending family gatherings, pool parties, or holiday celebrations, his eyes lit up when people came together. For the last 20 years, he took particular joy in hosting the Crazy Christmas House and Santa’s toy drive to support local Marine families.

Billy graduated in 1959 from Mary Star of the Sea High School in San Pedro. He officially clocked in as a longshoreman on his 19th birthday and was a proud member of the International Longshore and Warehouse Union (ILWU) Local 13 until 1985 when he was hired as a Foreman and became a proud member of the ILWU Local 94. He was a legend on the docks, often logging double shifts until he retired in 2017 after a total of 58 years of work that brought him joy and life-long friendships.

He was preceded in death by his parents Joseph and Mary, his brother Joseph, and his sister Lucretia. He is survived by his wife, Mary Lou, the love of his life for more than 44 years, his son Todd (Susan), daughters Kimberly and Lynne (Daniel), sisters Miriam (Gary) and Donna (Ben), grandchildren Louis (Brianne), Kelby, Brooke, Marley, and Micaela, and great grandson Cade. He is also survived by his nephews Michael, Steven, Brian, Joseph, Charles, and Samuel, and nieces Sarah, Billie Jo, Mary, and Emily, as well as over 25 great nieces and nephews and many other family, friends, and longshoring brothers and sisters who will miss him dearly.

Services will be held on Thursday, July 9th at Mary Star of the Sea Catholic Church in San Pedro, CA. The viewing starts at 10:00 AM, followed by a Catholic mass at 10:30 AM. From 12-4, all are welcome to celebrate his life at the ILWU Memorial Hall in Wilmington, CA.

Memorial donations may be made in Billy’s name to Santa’s Toy Drive 2026 benefiting local Marine families or a charity of your choice.