Officials listed the cause of death as an accident due to drug intoxication.
Coroner's officials said the official cause of death was determined to be complications of ischemic encephalopathy from methylenedioxymethamphetamine (MDMA) intoxication.
In effect, the ingestion of the hallucinogen caused Sasha to lose oxygen to her brain, leading to inactivity and death, said Dr. Marc Futernick, head emergency room physician at California Hospital Medical Center, where Sasha was treated.
Although a drug overdose had been suspected from the start, it took weeks for toxicology tests to be completed.
Futernick said Sasha arrived at the hospital in a coma. During the ambulance ride and for a short time after she arrived at the hospital, she experienced seizures, he said. Her sodium levels were severely low and she had abnormal heart rhythms, Futernick said. Two days after she was admitted, tests showed Sasha had no brain activity. On June 29, she was taken off a life support machine and pronounced dead.
Sasha and another critically ill patient had been taken to the downtown Los Angeles hospital by ambulance directly from the Los Angeles Coliseum on June 27, officials said. Both were treated for drug intoxication in the intensive care unit.
Doctors told Sasha's family that she had Ecstasy in her system when the ambulance got her to the emergency room. Although many partygoers consider Ecstasy to be safe, doctors and researchers warn that the drug can cause high blood pressure leading to stroke. The drug can also trigger seizures, releasing toxins that cause kidney failure.
The Electric Daisy Carnival, held June 26 and 27, drew about 185,000 people and featured carnival rides, five stages and performances by Moby, Will.i.am, Steve Aoki and Deadmau5. About 120 people had to be taken to local hospitals, mostly for drug intoxication.
A family spokesman said Sasha's mother and father did not know of her plans to attend the rave, which was restricted to people over 16 unless they were accompanied by a legal guardian.
Insomniac, the company that staged Electric Daisy Carnival, filed a seven-figure lawsuit against L.A. on Friday, claiming the city did not have proper cause to terminate a concert planned for Oct. 30 at the Los Angeles Convention Center.
In its complaint, the company cites more than a dozen recent deaths at or after major music or sporting events as an indication that their event was being unfairly singled out because of public perceptions of dance and electronic rave-like concerts.