The story I heard said that she would come out of this coma after a few days, but one time she did not and eventually doctors pronounced her dead. She was buried, but at her funeral her boyfriend (Charlie Garcia) heard her sream.
No one believed him, but eventually he had the body exhumed. When they opened the coffin they found her indeed dead, but...the lining of the coffin was ripped to shreds from the inside and fragments of the fabric found in ther hands.
This is the song he wrote. It's called "Rasguna Las Piedras" (Clawing the Rocks)