MARYSVILLE, Ohio (WCMH) – Sixteen people, including at least six children, were injured after reports of people being found unconscious in the pool area of a Marysville, Ohio, hotel Saturday evening due to what fire officials said was a high level of carbon monoxide.

According to Marysville Police Chief Tony Brooks, the calls started to come in at approximately 5:30 p.m., starting with a 2-year-old girl losing consciousness at the Hampton Inn on Square Drive. Dispatchers then received several more calls reporting people passing out.

Brooks said fire department investigators detected a life-threatening level of carbon monoxide in the pool area, causing people to become unconscious. He added that “multiple” people were affected by the incident.

According to a Memorial Hospital spokesperson, seven patients were taken to the hospital by ambulance and four people were walk-ins. Of the 11 patients at the hospital, five were adults and six were children.

The spokesperson said two patients were critical but stabilized, five patients were in serious but stable condition, and four patients were treated and released.

Sunday morning, the spokesperson updated that the affected patients were transferred to tertiary care facilities to continue their recovery.

Three other people were taken to Grady Hospital, and two others were treated at the scene.

Brooks said people reported symptoms of a burning throat and dizziness.

The hotel has been evacuated and remains closed. Officials have not said what caused the high carbon monoxide levels.