ORANGE, Calif.-- A 7-month-old baby boy who was tossed from the fourth floor of a hospital parking structure died Wednesday, the same day his mother made an initial court appearance on charges of attempted murder and felony child abuse, a police spokesman said.

The child died Wednesday morning at the University of California, Irvine, Medical Center and charges against the mother, Sonia Hermosillo, 31, will be upgraded to murder, said Sgt. Dan Adams, spokesman for the Orange Police Department.

Prosecutors allege that Hermosillo removed a helmet that her son wore for a medical condition before tossing him from the parking structure at Children's Hospital of Orange County late Monday. She then went back inside the hospital to validate her parking, senior deputy district attorney Scott Simmons said after Hermosillo's hearing.

Hermosillo's husband, Noe Medina, told The Orange County Register in an interview Tuesday that his wife had been hospitalized for postpartum depression in June after she said she didn't want their son, Noe Medina Jr., who was diagnosed with congenital muscular torticollis -- a twisting of the neck to one side.

The infant also wore a helmet to help correct his plagiocephaly, also known as flat-head syndrome, the Register reported.

"She didn't look at our son as normal," Medina said. "She didn't accept him. She didn't accept that he was like this."

Medina said the boy was receiving physical therapy twice a week and was showing signs of improvement.

Simmons, the prosecutor, said Hermosillo's behavior showed she intended to kill her son, regardless of her mental state.

"It's not like she's in a fetal position when the police arrived," he said. "She picks a specific location, drives to the top of the building (and) takes the helmet off. I'm sure she's depressed, the post-partum blues, I'm sure she had some of that."

"It's going to be up to a jury to decide if she had the wherewithal to inform the intent to kill."

Hermosillo made a brief court appearance Wednesday, but her arraignment was postponed until Sept. 16.

Orange County Superior Court Judge Joe Perez set bail at $1 million, but federal immigration officials have a no-bail hold to keep her in custody because she is in the U.S. illegally, said Jim Amormino, sheriff's spokesman.

Hermosillo is also on the medical ward, where she is being kept in a cell by herself and wearing a protective gown so she can't injure herself, he said.

The judge appointed a public defender for Hermosillo, but the attorney did not comment after the hearing.

Farrah Emami, spokeswoman for the Orange County district attorney's office said prosecutors were not commenting further on the infant's medical conditions, or a motive in the case.

"We're not going to speculate at this point as to why she may have done it. I don't think there will ever be a satisfactory answer as to why a mother would do something like this to her child," she said.

Adams said a witness on the ground saw the baby falling just after 6 p.m. Monday and several people, including a doctor, called 911.

Surveillance video showed Hermosillo's tan Chevrolet Blazer sport utility vehicle with an empty child seat leaving the parking structure a short time later, the sergeant said. The license plate was traced to Hermosillo's home.

During the investigation, La Habra police notified detectives that Medina had reported his wife and their son missing, Adams said.

An Orange police officer driving past Children's Hospital at 10:15 p.m. spotted the Blazer driving on a street about 100 yards from the crime scene and Hermosillo was at the wheel, Adams said.

Court records in Orange County indicate Hermosillo has no major criminal record but pleaded guilty to four traffic violations in La Habra in 2008, including driving without a valid license and having no proof of insurance.