There was another article that stated the police were treating the area with hazmat suits because of possible carbon monoxide suffocation.

https://www.sacbee.com/news/california/article253588249.html

https://www.fresnobee.com/news/local/article253577919.html

In 2018, there was the family that died in Tulum, Mexico from CO poisoning as well:

https://www.nbcnews.com/news/world/iowa-family-four-found-de...