William David Warner

William David Warner (Dave), 94, of Rockville, MD, passed away September 19, 2025, surrounded by his wife and six children.

Dave was born to William J. and Matilda Warner in Rochester, NY, but was raised in upper northwest Washington, DC. He attended Blessed Sacrament grade school, Gonzaga High School, and Georgetown University, where he earned degrees in accounting and business administration. He served in the U.S. Army from September 1953 to September 1955.

He married his wife Patricia (Pat) Slee in August 1955 and lived in Washington, DC. They moved to Wheaton, MD, in 1960 and to the Aspen Hill area of Rockville in 1966, where they lived for 57 years.

In November 1955, he went to work for the accounting firm Eric G. Jansson. He got his CPA in 1960, and sometime after Jannson retired, he and fellow CPA Mark Cunningham changed the name of the firm to Cunningham-Warner, which in November 1983 merged with Thomas Havey & Co. out of Chicago. He left Havey in November 1988 to become controller of the International Union of Operating Engineers until his retirement on June 30, 1996.

A devout Catholic, Dave was an altar boy at Blessed Sacrament and served as a lector, CCD teacher, and Arimathean at St. Patrick’s Catholic Church in Rockville, where he was a parishioner since the church’s inception in 1966.

He was a voracious reader of books, particularly on Catholicism and World War II history, and was an HO model railroader, meticulously building many wood kits and even some scratch-built trains. He was a lifelong baseball fan, first of the Washington Senators, then the Baltimore Orioles.

Dave was preceded in death by his four younger brothers: Tim, Mike, Denny, and Chris. He is survived by his wife Pat, six children – David (Catherine), Stephen (Cathy), Amy Wasel (John), Michael (Kim), Sally Amatucci (Eddie), and Judy Weixel (Pat) – and 20 grandchildren and 8 great-grandchildren. He was a beloved uncle to many nieces and nephews.

The family will receive relatives and friends beginning at 10:30 AM on Thursday, October 16, 2025, at St. Patrick’s Catholic Church, located at 4101 Norbeck Road, Rockville, MD 20853. The Funeral Mass will begin at 11:30 AM. Interment will follow at 1 PM at Gate of Heaven Catholic Cemetery in Silver Spring, MD.

In lieu of flowers, donations may be made to Our Lady of Bethesda Retreat Center, 7007 Bradley Boulevard, Bethesda, Maryland 20817, or online at https://olb.churchcenter.com/giving