Kimchi Truong, 24, collapsed at a taxi area last Saturday. She died Thursday at the hospital.
The Riverside County coroner is not ruling out a drug or alcohol overdose. He'll run toxicology tests to determine the exact cause, but that could take up to four weeks.
The festival kicked off its second weekend Friday.
Coachella's promoters say they're saddened by the death. They called it unfortunate, but isolated.