Carbon monoxide from a portable gas heater likely killed four people, including two children, as they slept in a combination camper-horse trailer ahead of a horse show, authorities said Friday.
The four, who were not immediately identified, were sleeping in bunks when they died Thursday night as they camped outside the Alliant Energy Center, where the World Clydesdale Show began Friday and will continue through the weekend.
The group was using the space heater to warm the trailer, Dane County Coroner John Stanley said. All four were related and from central Wisconsin but the adults were not the parents of the children.
Officials had no indication of foul play, and the investigation was continuing with carbon monoxide from the heater as a likely cause of the deaths, Police Chief Scott Gregory said.
Don Langille, a spokesman for Clydesdale Breeders of the U.S.A., said the four were longtime Clydesdale breeders and exhibitors who were well-known to everyone at the show.
“The majority of exhibitors will be saddened because they know everybody here, everybody grieves and they all grieve together,” Langille said.
It is common for people to sleep in a combination trailer. No horses were in the trailer at the time.
The trailer, about 20 feet long, was parked in a parking lot with dozens of other horse trailers behind the Alliant center and only feet from a fenced-in horse-showing area.
Ted Ballweg, sales and marketing director for the Alliant center, said the competition will proceed as planned. Between 10,000 and 15,000 people were expected to attend, he said.
It’s the first world competition for Clydesdale horses in the U.S. in more than 100 years, Ballweg said. The world competitions are typically held in Scotland or Canada, he said.