MEDICINE HAT, Alta. - Police say charges against a caregiver could be upgraded depending on results from an autopsy on a toddler who was allegedly assaulted in a southern Alberta day home.

The 18-month-old girl died in hospital Wednesday from head injuries. She had been taken by air ambulance from Medicine Hat to Alberta Children's Hospital in Calgary earlier this week.

A 23-year-old woman who was taking care of her at the private residence has been charged with aggravated assault and failing to provide the necessities of life.

Medicine Hat police anticipate those charges might be adjusted once the autopsy is complete, although Staff Sgt. Brent Secondiak says it will take a while to fully investigate what happened.

"There's lots of medical evidence we have to get from the medical examiner's office, from the hospital itself, witness statements to be taken, search warrants to be conducted on Alberta Health Services," Secondiak said. "It's just lots of statements and interviews that have to be done."

He said it's unknown how the girl sustained the fatal injuries and it's difficult to pull together the case because of trauma to her head.

The autopsy results won't be complete soon either.

"We'll know some things initially and some things such as toxicology ... will take weeks or months."

There may have been other children in the day home at the time, Secondiak added.

The accused has been released with orders not to contact the girl's family. Police have not revealed the woman's name because the charges haven't yet been filed before a judge. A court date of Sept. 7 could be moved up if they were upgraded.

Yvonne Fritz, the province's children and youth services minister, said the facility is licensed by the provincial government. She said the day home is a satellite of the Children's Corner day home agency in Medicine Hat, which has had a contract with the family services authority for 16 years.

Fritz said Wednesday the province will conduct an investigation.

"I can tell you that the findings of the investigation will be made public, and also that I will act on any changes that may be required," she said.

Nikki Grunwald, who owns a daycare in the area and is also the spokeswoman for the Medicine Hat and District Child Care Association, said doesn't think regulations for daycares and day homes need to be changed.

"For the majority, we're all doing what we're supposed to be doing, and I think it works, and it's just really unfortunate that in this case it didn't work," Grunwald said.

She said her biggest concern is for the little girl's family.

"I can't imagine what they're going through and it should never happen in a licensed facility."

Fritz has said the death was "a very unusual circumstance" and there are few problems in Alberta's 2,800 provincially accredited day homes.

She has directed the ministry to work with the day home agency to conduct a thorough investigation to ensure that all standards were being monitored. (CHAT TV)