Police Chief Jim Millin says Bryan Douglas Watts of Niles was pronounced dead at a nearby hospital. Millin says responding officers administered chest compressions to some children and helped get the affected kids into awaiting ambulances.
Two responding officers were treated for carbon monoxide exposure and released from the hospital.
Niles Fire Capt. Don Wise says the leak was caused by a malfunctioning vent pipe from the pool heater.
Choice Hotels, which owns Quality Inn, said in a statement that its thoughts were with the affected families, and that this "isolated incident" occurred at an independently-owned franchise.