I will add to this later (perhaps) but the picture says it all and it is hard to write about this sort of human behaviour causing such animal suffering. In happened in deep in woods in Butler County, Pennsylvania, USA. The animals were abandoned in their carriers in a wood as you see them. They starved to death. The picture is chilling. Some were in bins and bags.
“They were in locked carriers.”
Janice Lawniczak, who took pictures of the horrifying scene

Two useful tags. Click either to see the articles: Toxic to cats | Dangers to cats
It is believed that the people who did this are Tamara Rusz and Kevin Delehanty of Butler County. We don’t have pictures.

Useful tag. Click to see the articles: Cat behavior
Note: sources for news articles are carefully selected but the news is often not independently verified.