Robin Roberts' Mother Dies at 88

UP: Robin Roberts

The "Good Morning America" anchor lands a huge scoop with President Obama's same-sex-marriage interview, adding to GMA's recent momentum in its ratings battle with NBC's "Today."

Robin Roberts' mother, Lucimarian Tolliver Roberts, has died at the age of 88.

After Thursday's broadcast, Roberts flew to Mississippi to be near her mother's side; she died that day, Roberts' Good Morning America co-host, George Stephanopoulos, announced Friday morning.

"So much of what we love about Robin comes from her," he said.

ABC's Diane Sawyer, meanwhile, introduced a segment paying tribute to the elder Roberts, who was the first African American to head Mississippi's Board of Education. (View the clip here.)

STORY: Robin Roberts Announces Early Departure from 'GMA'

"Pure magic when she walked into the room ... and of course Robin knew .. her heavenly instincts always tell her when she needs to be there with her family," Sawyer said.

Roberts left GMA a day before her previously announced medical leave was scheduled to begin. She is in preparations to undergo a bone marrow transplant to treat her myelodisplastic syndrome, which is a rare form of leukemia.

"Our beloved mother, the matriarch of our family, 88-years-old, has had some health issues recently and it's got to the point that Sally-Ann and I need to get home so I'm leaving a day early," Roberts explained. Her sister, Sally-Ann, is her bone marrow donor.