A 27-month-old girl who fell into cardiac arrest while receiving general anesthesia before surgery at an eye hospital in Ulsan has passed away 11 days after the accident.

As the possibility has been raised that the oxygen respirator circuit was incorrectly connected during the administration of anesthesia, police are investigating three individuals, including the hospital director and medical staff, on charges of professional negligence resulting in death.

According to the Ulsan Jungbu Police Station, the victim, identified as child A, who suffered the accident on October 2, had been receiving treatment at a hospital and passed away on the afternoon of October 13.

The mother of child A shared the news of her daughter's passing on social media, writing that she was a baby who was smiling and spending time with her family just two weeks ago, and that she cried out and prayed to every god in the world, but her daughter still departed.

She also made an emotional plea, saying she wants to know if the accident could have been prevented, and if it could have been prevented, why it was not.

At the time, child A was scheduled to undergo surgery at an eye hospital in Jung-gu, Ulsan, to treat entropion.

Entropion is a condition where the eyelashes turn inward and irritate the cornea.

However, suddenly, cardiac arrest occurred while she was receiving general anesthesia prior to the surgery.

After receiving emergency treatment at a nearby hospital and recovering her heartbeat, child A never regained consciousness.

She was subsequently transferred to a university hospital in another region for treatment, but passed away 11 days after the accident.

Immediately following the accident, the eye hospital explained that oxygen was not properly supplied during the anesthesia process.

The hospital previously stated that the attending anesthesiologist also admitted to a mistake.

The possibility of an incorrect connection in the oxygen respirator circuit has been raised as the specific cause of the accident.

It was reported that the freelance anesthesiologist in charge of the anesthesia at the time explained to the bereaved family days after the accident that, upon inspecting the equipment, the two circuits for air intake and exhaust appeared to have been connected in reverse.

Following the death of child A, police changed the charges against the three individuals—the hospital director, the anesthesiologist, and the surgeon—from professional negligence resulting in injury to professional negligence resulting in death.

An autopsy was conducted yesterday to determine the exact cause of death, and evidence related to the surgery was secured through a search and seizure at the hospital.

The circumstances surrounding why the operating room CCTV was not recording are also under investigation.

Police plan to review factors such as the timing when CCTV recording obligations take effect to determine whether there were any violations of the Medical Service Act.

(Reported by Kim Minjeong | Video by Lee Da-in | Graphics by Lee Su-min | Produced by SBS Digital News)