Anyialah Greer, 9, was referred for tonsillectomy to cure her sleep apnea, but after the operation, she never woke up.

According to Inside Edition, Greer never fully regained consciousness despite doctors telling that she would wake up 15 minutes after the surgery. The child died just a few hours after the surgery.

Gambrell is planning to press charge against Detroit Medical Center, which owns the Children's Hospital of Michigan, where Greer underwent the surgery just weeks before the Christmas.

Detroit News said the procedure which normally lasts only for 40 minutes took two hours to finish.

Medical reports obtained by Gambrell and shared with The Detroit News indicate Greer could have had an obstructed airway, issues with anesthesia or an undetected heart condition before dying of cardiac arrest.

"Under federal law, you can't discharge people unless they're in stable condition. I don't know how she could be considered stable when she died just hours after discharge," Gambrell's attorney, James J. Harrington IV, who specializes in taking cases concerning medical malpractice said.

Bianca Siegel, the ear, nose, and throat specialist who conducted the surgery issued the discharge order.

In an interview with New York Daily News, Dr. Richard Rosenfeld, professor and chairman of otolaryngology at the State University of New York Downstate Medical Center in Brooklyn said tonsillectomy is a low-risk procedure and the the third most common childhood surgery, second only to circumcision and ear tubes.

This is why Gambrell is still trying to figure out how such kind of surgery would lead to her daughter's untimely death.

Meanwhile, the Children's Hospital released a statement about Greer's death, saying:

"We were deeply saddened to hear of the passing of Anyialah. We take the care and service we provide to our patients very seriously and we are here to support the family during this difficult time."

Autopsy reports are not yet on hand.