Brooke Ellison’s “first life,” as she called it, ended on Sept. 4, 1990, when she was 11 years old. It was the day before the start of seventh grade. She was crossing a busy street on her walk home from orientation at her junior high school in Stony Brook, Long Island, when she was hit by a car.

The impact cracked open her skull, broke nearly every major bone in her body and left her in a coma for 36 hours. When she awoke, she learned she had been paralyzed from the neck down. For the rest of her life – her “second life,” she said – she depended on a ventilator to breathe and a motorized wheelchair, which she controlled with her mouth, for mobility.

Brooke Ellison, a tireless advocate for disability rights, was paralyzed from the neck down when she was hit by a car at age 11. Stony Brook University

Defying all expectations, she underwent months of rehabilitation and returned to school for the beginning of eighth grade. She graduated from high school and was admitted to Harvard University, where she studied cognitive neuroscience.

She remained at Harvard after her undergraduate training to receive a master’s degree in public policy and then earned a doctorate in sociology from Stony Brook University, where she joined the faculty, teaching courses that touched on medical ethics, stem cell research and sociology.

Dr. Ellison, who outlasted by nearly a quarter-century the nine-year life expectancy she was given at the time of her accident, and who emerged as a tireless advocate for disability rights, died Feb. 4 at a hospital in Stony Brook. She was 45. The cause was complications from quadriplegia, said her parents, Edward and Jean Ellison.

Ellison recounted her story in a memoir, “Miracles Happen” (2001), which she co-wrote with her mother and which inspired a 2004 TV movie, “The Brooke Ellison Story,” directed by Christopher Reeve. Reeve, the “Superman” actor who was paralyzed from the neck down in an equestrian accident in 1995, died days before the movie aired.

“I didn’t want people to focus on what I had lost in my life, but rather on what I still had in my life,” Ellison told the New York Times in 2005. “Thankfully my accident did not rob me of my ability to think, reason or remain a vital part of society. My body would not respond, but my mind and my heart were just the same as they had always been.”

Brooke Mackenzie Ellison was born in the Long Island town of Rockville Centre on Oct. 20, 1978, the second of three children. Her father worked for the Social Security Administration. Her mother, who had started a job as a special-education teacher the day of Brooke’s accident, became her daughter’s constant caregiver and champion.

Before her accident, Brooke filled her after-school life with dance, sports, karate, cello lessons and choir practice. When she emerged from her coma, she asked immediately if she would be held back in school. With help from tutors, and through her own determination, she was not.

Beginning in Brooke’s eighth-grade year, her mother attended school with her to tend to her medical needs, which the school nurse was not trained to meet. Jean Ellison raised her hand on her daughter’s behalf when Brooke had a question in class. She turned the pages of the books her daughter was assigned to read. But Brooke did the work.

When Brooke entered Harvard, her mother also moved into the dormitory suite, which the university had renovated with features including a hydraulic lift and an electronic door opener. Brooke started a student group on disability rights and received a bachelor’s degree in 2000 with an honors thesis on “The Element of Hope in Resilient Adolescents.” She received her master’s degree from the Harvard Kennedy School in 2004.

She paused her schooling to run as a Democrat for a Long Island-based seat in the New York state Senate in 2006, the year she turned 28. She lost to the incumbent Republican, John J. Flanagan.

Returning to graduate school, she received her doctorate in 2012 from Stony Brook University, where she taught in the university’s School of Health Professions until her death.

Ellison served on the Empire State Stem Cell Board, helping to oversee New York state policy on stem cell research, which has shown promise in the treatment of spinal cord paralysis.

In other advocacy efforts, she worked with health-care and technology companies to improve products for disabled people. For years, her independence was vastly increased by a retainer-like device that sat on the roof of her mouth and allowed her to control her wheelchair and computer – and even turn the television or lights on and off – by tapping her tongue.

When the company that made the retainer went out of business, Ellison was left with a more primitive device that allowed her to control only her chair. She felt as though she had been paralyzed again, her parents said. Until her death, they said, she was testing new devices that might enhance the lives of people with disabilities.

Besides her parents, both of Stony Brook, survivors include a sister and a brother.

Ellison wrote a second memoir of her life after her accident, “Look Both Ways,” published in 2021.

“There’s not a day that goes by that I don’t think what if … what if I didn’t cross that road that day or didn’t decide to walk home from school that day. Where would I be right now, what would I be doing?” she once told an interviewer.

“It didn’t (take) long for me to realize that all of those things are purely hypotheticals no less real than any other way we could have envisioned our lives,” she continued. “What we have right now is all that matters.”