(CNN) -- Hall of Fame women's track and field coach Bev Kearney, whose story of recovery from a paralyzing auto accident inspired people around the country, has resigned due to an "intimate consensual relationship" with a University of Texas athlete in 2002, the school announced Saturday night.
The head of the university's legal affairs department said in a written statement that Kearney was a good person who was important to the school.
"However, she made this terrible mistake and used unacceptably poor judgment in having this relationship," Patti Ohlendorf said.
The relationship began 10 1/2 years ago and ended "at least about eight years ago," the statement said.
Neither the university nor Kearney, who first told the Austin American-Statesman of her decision to step down, identified the athlete.
"You destroy yourself. You start questioning how could you make such a judgment," Kearney told the newspaper. "How could you make such an error after all the years? You can get consumed (by it)."
A CNN story in August profiled the coach, who learned to walk again after she was injured in a December 26, 2002, accident that killed two of her friends.
Thrown more than 50 feet from an SUV, she suffered extensive spinal injuries that left her partially paralyzed.
Kearney said she never doubted her ability to walk again and continued to lead her team from her hospital bed.
"When they told me I was paralyzed, it went in one ear and out the next ... because I had to get up and coach," she said.
Track practices were recorded and then played for Kearney on a VCR in her hospital room.
"Because I was an intuitive coach ... whatever it is you need to do, I can describe it in a way that you internalize it and you feel it without me having to demonstrate it," she said.
She also started a foundation that connects young people with mentors.
"If I can expose you to the best ... it has a great chance of inspiring you to be the best," Kearney explained.
Kearney's teams at Texas won six national championships, the most recent in 2006. She also led the University of Florida Gators to a title in 1992. She was inducted into the U.S. Track & Field and Cross Country Coaches Association Hall of Fame in 2007.
"(My athletes) would say that I'm tough. That I believe in being the best you can be at all times," she told CNN. "I am going to demand their best, and I am relentless at it."
Kearney, 55, told the American-Statesman that she might have to sell her home and some of her personal possessions to help support the daughter she adopted after the girl's mother was killed in the 2002 accident.
The paper said her attorney, Derek A. Howard, issued a statement, which said in part: "We believe that Ms. Kearney has been subjected to a double standard and has received far harsher punishment than that being given to her male counterparts who have engaged in similar conduct. ... It is a shame that this remarkably talented female African-American coach, who has devoted her life to helping others, is being bullied and scapegoated by the University of Texas."
Ohlendorf denied Sunday that gender played a role in the university's review and said she knows of no other "UT head coach who has entered into such a relationship with a student-athlete on his or her team."
Kearney was the first African-American coach to win an NCAA national team championship in Division I track and field, and she was the first African-American to serve as a head coach at Texas.
Howard said Sunday that Kearney was given until Monday at noon to resign or she would be fired.
He said the relationship wasn't specifically against school policy, but the rules require someone in a supervisory role to report such a relationship.
"It's not a terminable offense," he said. "She was a perfect coach before and prior to the relationship. She had a pristine record. Why anyone would think she is not a suitable coach is mind-boggling to me."
Ohlendorf called such a relationship "unprofessional and unacceptable."
"We told Coach Kearney and Mr. Howard that such a relationship crosses the line of trust placed in the head coach for all aspects of the athletic program and the best interests of the student-athletes in the program," she said in an e-mail to CNN Sunday night.
Ohlendorf said the school is not naming the student, citing privacy laws.
"We respect her privacy and appreciate her cooperation during our review," Ohlendorf said.
The ex-student reported the former relationship to the school in late October, she said, leading to Kearney being placed on leave in November.
The school said the athlete was an adult when the relationship took place and it had no information that Kearney had any other similar relationships.
The Longhorns' indoor track season begins on Saturday.
CNN's Ashley N. Vaughan contributed to this report.