You probably weren't wondering how factory farmers are killing the glut of pigs that can't be brought to slaughter due to the the surge of COVID-19 in the meatpacking industry that has shuttered slaughterhouses, but here's how: cooking them alive in their cages.
It's called "ventilation shutdown," and it's exactly what it sounds like. They shut off the ventilation and walk away.
This is the method the poultry industry calls "humane." To make it even more humane, they sometimes vent heat INTO the facilities to accelerate dehydration and heat stroke. poultryworld.net/Health/Article… 
Here are some other methods the American Veterinarian Medical Association suggests for "depopulation" of pigs: gunshots, electrocution, and "concussive force on the brain."
