These sad events should be a reminder that vehicle engines should NEVER be run in an enclosed space, except of course very briefly when required to drive the vehicle in or out.

Most people are aware of the danger of running the car engine in a garage whilst someone is in the garage.
Not everyone realises the risks of a garage attached to living spaces, into which fumes may pass.

Modern vehicles are often fitted with catalyitic converters, this slightly reduces the risk, but only slightly it is still dangerous to run a car engine in an enclosed space.

Portable generators are also a risk, every year people die from useing them indoors, or outside but near enough that fumes enter living areas.