Thirteen persons including six children were rushed to the hospital on Saturday when hotel staff found children lying unconscious around the indoor pool of the Quality Inn and Suites in Niles, Michigan. According to Niles Police, a local 13-year-old boy identified as Bryan Douglas Watts later died en route to the local hospital.

Carbon monoxide leak cause of death

WSBT22 News interviewed Niles Fire Captain Don Wise at the scene who confirmed that high levels of carbon monoxide were found in the hotel pool area with lower levels found in other parts of the hotel.

Later a mechanical engineer inspection revealed that a pool heater malfunction was the cause of the deadly CO leak according to the Niles Fire Department.

Niles Fire Captain Don Wise told NBC, "Carbon Monoxide is odorless, colorless, tasteless. You'll wind up getting flu-like symptoms, vomit, then go unresponsive but there isn't much time between getting nauseous and going fully unconscious." Captain Wise stated that there were issues with the ventilation system on the heater and the exhaust had not been functioning properly. The hotel is shut down for repairs.

Niles Police Chief Jim Millin told NBC that in the pool area and maintenance room the hotel's carbon monoxide monitor reported levels 16 times the safety limit at 800 parts per million.

According to the US Environmental Protection Agency (EPA) website, the permissible exposure limit from the National Institute for Occupational Safety and Health is 35 parts per million in an 8-hour time-weighted average concentration, with 200 ppm as a ceiling.

Remaining children expected to recover

The other children ranging from ages 12 to 14 were taken to Memorial Hospital in South Bend, Indiana.

A Lakeland Health Hospital representative told NBC News that the remaining children are expected to make a full recovery. In addition to the guests, a hotel worker and two County and city police officers were treated for carbon monoxide exposure and later released.

Choice Hotels, the parent company of Quality Inns and Suites, released a statement, according to CNN, that says they are “working closely with local officials to manage the situation, saying,"Our highest priority is always the safety and well-being of our guests.”