Mary Ann Haas (Slaker), of Concord, beloved wife of 49 years of William L. Haas, died peacefully on October 15, 2025, at the age of 84.

Born in the Bronx, on December 9th, 1940, Mary Ann was the eldest of 3 daughters of Mary and Frank Slaker. Mary Ann was an excellent student, receiving the general excellence medal upon both her graduation from St. Frances of Rome school in the Bronx, and from St Gabriel High School in New Rochelle. She was awarded a full scholarship to the College of Mount Saint Vincent in Riverdale. She graduated with a BS in Chemistry, and began employment as a chemist for Lederle Laboratories in Pearl River, NY. In 1964, she joined AT&T as a computer programmer. She worked for a couple of start up companies in Manhattan as a programmer, analyst, and in sales support. Mary Ann then joined CIT Financial as Director of Computer Education. During this period, she attended New York University graduate school in the evening, and received her MBA in Information Systems and in Management. She graduated with Distinction, and was received into the Beta Gamma Sigma honor society.

It was at this time, Mary Ann met her future husband, Bill, in Manhattan. They married in 1976, and moved to Concord Massachusetts. She spent the next 16 years working for Digital Equipment Corporation, where she started and managed the Customer Support Center in Massachusetts. At Digital, she served on the Corporate Contributions committee for Women's Education and Advancement and promoted women's education in science and mathematics. Mary Ann joined the Beta Gamma Sigma society of New England and became Vice President. She also started the New England chapter of Women in Information Processing and served as its first president. Upon retirement from Digital, Mary Ann joined her husband in the Financial Planning business, and assisted him for 8 years.

Mary Ann enjoyed a very active retirement. She was an avid bridge player, enjoyed golfing, gardening, travel, and dabbled in photo and video editing. Bill and Mary Ann were members at Nashawtuc Country Club, and for over 30 years, they were members of the Concord/Carlisle couples bridge group. Mary Ann was also a member of the Concord Garden Club

Mary Ann was a devout Catholic, and her church community was an important part of her life. She was an active member of Holy Family parish, and served as a Eucharistic minister in church, to the home bound, and at Emerson Hospital. She served on the parish finance committee and on the flower committee. Mary Ann was also a member of the Finance Committee for the Town of Concord. For many years, she was a volunteer money manager for the elderly through Minuteman Senior Services.

At home, Bill and Mary Ann both fondly enjoyed their little Shih tzu's Teddy, Suzie and Daisy. Family and friends were the most important part of Mary Ann's life. When her sister Terri was young, she often invited her to her apartment in Manhattan for special, cultural event weekends. She introduced her to Broadway, opera, museums, and fine dining. They would often fondly reflect on those incredible experiences. She also enjoyed providing a vacation in Concord for her niece and nephews from New York, and loved hosting holidays for the family. She enjoyed cooking and baking, and displayed her abilities at many gatherings with friends. Family and friends alike, delighted in and appreciated the loving and caring manner in which she shared her culinary talents.

She is survived by her husband Bill, her sister Terri Sorel, nephews Jason and Jeffrey Sorel, a great nephew and great nieces, her Aunt Rose and many cousins. Mary Ann was predeceased by her parents and her sister Joan Irizarry, her nephews Frank and Nick Irizarry, and her niece Tricia Prentice. She was profoundly loved and will be deeply missed. May her return home be joyous.

Family and friends will gather for visiting hours at Dee Funeral Home, 27 Bedford Street, Concord Center on Thursday, October 23rd from 6 to 8 pm.  Mary Ann's Funeral Mass will be celebrated on Friday, October 24th at 11 am in St. Bernard's Church at Holy Family Parish, 12 Monument Square, Concord Center.  Burial will follow at Sleepy Hollow Cemetery, Concord.

Arrangements are entrusted to Dee Funeral Home & Cremation Service of Concord.