Lucimarian Roberts, the mother of " Good Morning America" anchor Robin Roberts, died Thursday at the age of 88.

"It is with deep regret and heavy prayer and reflection tonight that I write to tell you of the passing of Robin's beautiful and inspiring mother, Lucimarian," Tom Cibrowski, executive producer of "GMA," wrote in an email early this morning to ABC staff.

Roberts was with her mother in Mississippi at the time of her death after leaving "GMA" Thursday, a day earlier than she had planned to depart the show to begin an extended medical leave for treatment of the bone marrow disorder MDS.

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Roberts traveled to the family's home, which had been in the path of Tropical Storm Isaac, Thursday with her older sister, Sally-Ann Roberts, who has been in New York City preparing to be the bone marrow donor for Robin.

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"Robin arrived home with her sister Sally-Ann, forging through flooded and blocked roads to be with her beloved mother in time to see her," Cibrowski wrote.

Lucimarian Tolliver Roberts was the first African-American to head Mississippi's Board of Education. Her passion for music and poetry led her to write a book this year titled "My Story, My Song," on which Robin Roberts collaborated.

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"I sing because the music of the church speaks my soul language," she wrote in the book. "I sing because these songs are tightly woven in to the texture of who I am."

The cause of Lucimarian's death was not announced. In addition to Robin and Sally-Ann, Lucimarian Roberts is survived by two other children, a son, Butch, and daughter Dorothy.

The family said they plan to hold a small private memorial service.