(Photo by Amaury Laporte)

Investigators say that faulty electrical wiring caused a handrail to electrocute a six-year-old girl at MGM National Harbor in June, the Washington Post reports. The shock caused the little girl to go into cardiac arrest, and she has been hospitalized for critical injuries in the three months since, according to the outlet.

The Post obtained a report from Prince George’s County officials investigating the incident. According to that report, a device meant to reduce the flow of electricity to lights illuminating the underside of the handrail—called an LED driver—was improperly installed, charging the handrail with 120 volts of electricity. The child was playing on the handrail with her brother when she was shocked with 120 volts, the Post reports.

“This was a tragic accident and our thoughts continue to be with the young girl and her family,” MGM spokesman Gordon Absher told news outlets in a statement. “The safety of our guests is something we take very seriously. MGM National Harbor has been working closely with multiple county agencies, including the County Fire Department and independent forensic experts, in their efforts to determine a cause. As this is an ongoing review, we cannot comment until official conclusions are presented and a final report is issued.”

The LED drivers were not the only problem, however. The electrical wiring powering the lights under the handrail was meant to be used for things like voice, data, and audio—not LED lights, according to the Post’s account of the report. Also, the handrail itself was loose. Investigators have also found other electrical issues at the property, including more improperly installed LED drivers.