Longtime Montgomery County school board member Patricia O’Neill, who died Tuesday, was remembered as a champion for education reform and a passionate public servant.

O’Neill, 71, who was first elected to the school board in 1998 and in her sixth four-year term, was the longest-serving member of the Montgomery board. She had served as board president five times and vice president six times.

O’Neill’s husband, Rick, said she died suddenly, while watching a live-streamed meeting of the Montgomery County Council in the family room of her home. She slumped over and could not be resuscitated by paramedics, he said.

While doctors have not identified the cause of death, the family does not believe it was related to the coronavirus. The O’Neills, who were fully vaccinated, had recently traveled to London to see their younger daughter, Melissa, as she planned her wedding, and they had been tested repeatedly as part of travel requirements.

Rick O’Neill said that his wife of 49 years loved her work with the Montgomery County school system and that she had little interest in seeking higher elected office. The two of them had grown up attending the county’s public schools — both graduated from Walter Johnson High School in 1968 — and she was an energetic believer in the 160,000-student system, the largest in Maryland.

“She was just dedicated to the children of the county and the schools of the county and was just everything you would want in a public servant,” her husband said.

County and Maryland state leaders mourned the loss of O’Neill.

“Pat O’Neill was a fierce champion for staff, students and families and the impact of her work will live on for generations,” interim schools superintendent Monifa McKnight said in a statement. “I am grateful for her service, her leadership, and her guidance and will miss her wisdom and partnership.”

Board President Brenda Wolff said in a statement: “We have lost an impassioned advocate for children, students and our community. Mrs. O’Neill leaves a legacy of educational excellence that will guide our work for years to come.”

Montgomery County Council member Craig Rice (D-District 2) remembered O’Neill as a key supporter for educational reform and curriculum changes. Her impact was felt in the ways she advocated developing the “whole child” and understanding the importance of social and emotional education for children, Rice said.

“It was good to have someone on there who understood the history and where the county had come from, but also embraced the changes that needed to happen,” Rice said.

Council member Nancy Navarro (D-District 4) said that shortly after they began working together, she saw O’Neill as the person to turn to for guidance.

“I realized she was the repository of so much institutional knowledge,” Navarro said. “It was amazing, everything she could cite.”

Her favorite memories with O’Neill, though, were the times she would listen to her talk about her daughters and grandchildren. She would share advice on how to balance being a mother and an elected official.

“She really touched everybody,” Navarro said.

A graduate of Southern Methodist University, O’Neill served as chair of the Montgomery school board’s policy management committee and as a member of the fiscal management committee. She also served as vice chair of the Montgomery County Public Schools Educational Foundation.

“The Council has lost a colleague, friend and a champion for children. Mrs. O’Neill always put our young people first and was committed to investing in teachers and support staff to deliver world-class educational opportunities to support student success,” Montgomery County Council President Tom Hucker (D-District 5) said in a statement Tuesday night.

O’Neill had also served as president of the Maryland Association of Boards of Education and co-chair of the Washington Area Boards of Education. In 2015, the Washingtonian named her as one of the most powerful women in Washington.

Montgomery County Executive Marc Elrich (D) said he was saddened to learn of O’Neill’s death. “Her love of our children was only matched by her commitment to the constituents she served for nearly a quarter of a century,” Elrich said in a statement.

On Sunday night, O’Neill had celebrated the 10th birthday of her granddaughter, Brooke, in Falls Church with family members — her husband, her elder daughter, Jennifer Schiffer, and son-in-law Dan Schiffer, her grandson, Will, and her sister, Carolyn O’Conor, a physician in Montgomery County.

“She was very, very happy Sunday night and just working away today, watching the County Council,” her husband said.

O’Neill was up for reelection in 2022. According to the board’s handbook, the remaining members will select someone to serve the remainder of her term. The handbook says the school board will take applications from those interested, and selected candidates will be interviewed and voted on in a public session. Candidates must live within the same district and be registered to vote in Montgomery County.