Authorities in Mississippi are trying to piece together the last hours of a 19-year-old woman who was set on fire and left to die. They were reviewing surveillance video that shows the woman, Jessica Chambers, at a convenience store gas station less than two hours before she was set on fire, and also investigating what she managed to whisper to firefighters before she died. Deputies responded to a call Saturday about a burning car in Courtland, Mississippi, and found Chambers on fire outside the vehicle, the Panola County Sheriff's Office said. She died of thermal injuries at a hospital, with preliminary autopsy results revealing severe burns over 98 percent of her body. Authorities were reviewing Chambers' cellphone records and talking to possible witnesses, who could become suspects, said Jay Hale, an assistant district attorney who prosecutes cases in Panola County. Hale said Chambers spoke with firefighters on the scene before she was taken to a Memphis hospital, where she died. Hale said he could not discuss what she said. "She was able to communicate. It was difficult," he said.