A 13-year-old boy died and at least six other children were rushed to hospital unconscious after a carbon monoxide leak at a hotel pool.

Bryan Douglas Watts, 13, was pronounced dead at a nearby hospital after the incident at the Quality Inn & Suites in Niles, southwestern Michigan.

Emergency services rushed to the hotel on Saturday morning after staff found six children lying unconscious on the pool deck. A seventh child was later discovered passed out in a first-floor room.

The boy who died was local to Niles, a small town of about 11,000 people.

The other children found unconscious were all aged between 12 and 14, the spokesman said.

Two responding officers were treated for carbon monoxide inhalation but later released from hospital.

Niles Fire Captain Don Wise said the leak was caused by a malfunctioning vent pipe from the pool heater.

Police said that, when they arrived, carbon monoxide levels at the hotel were 16 times the safe limit for the US.

Carbon monoxide, sometimes referred to as "the silent killer", is an odourless, colourless and tasteless gas produced when a fuel is burned. When too much of it is in the air, it can replace the oxygen in red blood cells and cause tissue damage or death.

Choice Hotels, which owns Quality Inn, said in a statement it is “working closely with local officials to manage the situation. ... Our highest priority is always the safety and well-being of our guests.”

The statement added that its thoughts were with the affected families, and that this “isolated incident” occurred at an independently-owned franchise.