"She would text and drive. Our friends told her she needed to stop," Simmons said. "I think many teens, or anybody, can learn from her mistake."
Chief Deputy Coroner Mark Bowen said that mistake, combined with speeding, might have led to the fiery crash that killed the Hephzibah High School homecoming queen less than two days after her graduation.
Her flip phone was found lying open, next to her body.
"It appears that she was," Bowen said. "We're not sure 100 percent but that's the way it was looking."
Bowen said officials will subpoena Miller's Verizon Wireless cell phone records to determine whether she was using the phone at the time of the accident. It will take about two weeks to receive the phone records, he said.
Miller, 18, graduated from Hephzibah High on Tuesday afternoon. On Wednesday night, Miller was traveling west in the 1900 block of Hephzibah McBean Road when she lost control of her Chevy Aveo and ran off the road. Her car struck a power pole, snapping it in half and causing Miller to be ejected from the vehicle. The car burst into flames.
Miller was partially trapped under the vehicle and suffered burns over most of her body, which caused her death, Bowen said. She was pronounced dead shortly before 1 a.m. Thursday.
The news shocked fellow Hephzibah students who gathered at the school Thursday. About 100 of them stood for hours in the heat consoling each other and sharing memories of the girls soccer and volleyball team captain.
Many described her as funny, outgoing and down-to-earth in spite of the popularity that brought her the homecoming queen title last fall.
Elizabeth Alspaugh had last seen Miller moments before she crossed the stage at James Brown Arena on Tuesday. Alspaugh, who had known her since middle school, warned Miller of the slippery stage.
"I said, 'Be careful.' She was like, 'Girl, I got this,' " Alspaugh recalled. "She was just such an inspiration. She motivated us."
Alspaugh and Miller both served as captains of the volleyball team.
She was set to play volleyball on a scholarship for a small school in Wisconsin, Simmons said.
Hephzibah High principal Walter Reaves said students and staff gathered at the school on Brothersville Road to memorialize Miller about 9 a.m., and were still there about 1 p.m. A psychologist and guidance counselor were on site to provide grief counseling.
"I think the testament to her is that students are continuing to gather out here," Reaves said Thursday.
Next to her senior photo, a quote reads, "Live life like it's your last."
Hephzibah High senior Ikeyla Hughes will take Miller's words to heart, she said.
"I'm going to be a lot more careful," she said. "Texting can have a huge impact. This makes me see how serious it can be."
Staff Writer Adam Folk contributed to this article.