The 21-year-old had actually died in the crash, and her friend, 19-year-old Abby Guerra, was the one in critical condition with a brain injury, broken back, collapsed lung and other injuries.
Guerra's family had spent the past week planning her funeral, and teammates from Guerra's University of Evansville soccer team in Indiana planned to fly to Phoenix to attend it. But her family and friends rushed to her bedside Saturday after learning of the mix-up.
"It's a miracle but ... you feel angry because we mourned all week," Dorenda Cisneros, Guerra's aunt, told KPHO-TV in Phoenix on Sunday.
Cisneros said trying to come to terms with the news of Guerra's death was like a bad dream, and the family is hopeful someone will be held accountable for the mistake.
"You just don't want this to ever happen to somebody else, you know? To point fingers and this and that doesn't do any good," she said. "We just want ... some changes to be made so families don't have to go through this."
The Arizona Department of Public Safety said in an e-mail to The Associated Press on Sunday that a spokesman wouldn't be available to discuss the identification mistake until Monday.
Cantu and Guerra were among a group of five friends from Ironwood High School in Glendale, outside Phoenix, who were returning from Disneyland on July 18 when the sport utility vehicle they were in blew a tire. The driver lost control, and the SUV rolled several times, authorities had told the families.
One of the five - 20-year-old Tyler Parker - was taken to St. Joseph's Hospital and Medical Center in Phoenix, where he died the next day. A woman believed to be Cantu and another person suffered severe head trauma and were also taken to St. Joseph's. Officials incorrectly said Guerra had died at the scene, The Arizona Republic reported Sunday.
The ordeal was devastating for Cantu's parents, said longtime Cantu friend Colleen Donovan.
"Every day they went (to the hospital) having hope that she's living one more day, then to find out it's not her," Donovan told the Republic. "And Abby's parents, too. They've gone through all these emotions, and now they find out she's really alive. Abby still has a struggle to survive."
Donovan said dental records were used to correctly ID the women. Donovan never suspected that the girl lying in the hospital bed was Guerra. The girl in the hospital had her head shaved for brain surgery. Her face was swollen and her eyes blackened, Donovan said.
Donovan never suspected that the girl lying in the hospital bed, who had her head shaved for brain surgery, was Guerra. The girl in the hospital also had a swollen face and black eyes, Donovan said.
"You're not looking for differences," she said. "It didn't look like anyone I'd ever seen."
A similar situation happened in Indiana in 2006, when a deadly traffic crash drew widespread attention after two families discovered one of the victims had been misidentified as a survivor.
The two young women were similar in appearance, and the family of the one who died had kept vigil for five weeks at the bedside of the survivor, Whitney Cerak, believing she was their daughter. Cerak's family had buried 22-year-old Laura VanRyn's body, believing she was Whitney.