Catlynne Shaw had been in critical condition after having a heart attack while on a ride at Circus Circus Adventuredome July 16, the Las Vegas Review-Journal reported Wednesday.

Ed Granil, a Clark County Fire Department engineer who was off-duty at the park, revived Shaw after she fell unconscious while riding the Canyon Blaster, the newspaper said.

The Review-Journal said Granil performed rescue breathing on the girl and aided security officials in using an automatic external defibrillator to save her.

Authorities have not revealed the specific cause of Shaw's Tuesday death or whether she had existing heart conditions.