• 911 received several calls about multiple people lying unconscious by the pool
  • Investigation into the source of the carbon monoxide is underway
  • CO is an odorless and colorless gas that can be fatal if inhaled continuously

Over a dozen people were hospitalized after an incident at a hotel swimming pool in Ohio. They inhaled "life-threatening" amount of carbon monoxide.

Authorities responded to a call Saturday evening about a young girl who was unconscious at the Hampton Inn in Marysville, Ohio, CNN reported, citing Police Chief Tony Brooks. Soon, however, the 911 center received more calls about people falling unconscious around the pool area, while others described symptoms including "dizziness and a burning in their throat," according to Brooks.

Evidently, there was "life-threatening levels" of carbon monoxide (CO) around the pool area of the hotel, Marysville Fire Chief Jay Riley said, as per CNN. First responders took nine people to local hospitals while four more went on their own. Two others were evaluated at the scene but were not taken to a hospital.

While the ages of the patients were not disclosed, it was reportedly a mix of children and adults, according to The Columbus Dispatch. The other guests and staff of the hotel also evacuated the facility, with the hotel management reportedly arranging their stay at other hotels.

Carbon monoxide is an odorless and colorless gas that can actually kill people, the U.S. Centers for Disease Control and Prevention (CDC) noted. Breathing in a lot of it can cause a person to pass out or even die, with those who are drunk or sleeping running the risk of dying before they even develop symptoms.

"Everyone is at risk for CO poisoning," the CDC noted. "Each year, more than 400 Americans die from unintentional CO poisoning not linked to fires, more than 20,000 visit the emergency room, and more than 4,000 are hospitalized."

So far, several of the people who were hospitalized have been released while others have been transferred to tertiary care facilities. The investigation on the exact source of the carbon monoxide is still underway.

"We continue the investigation into the source and (are) glad that no one died as a result of their exposure," Riley said, as per CNN.

"The Hampton Inn Marysville is fully cooperating with the local authorities as they investigate the incident," a spokesperson of the Hampton Inn said in a statement to ABC News.

Swimming Pool
Water in a swimming pool. Pixabay