- Total blackouts worldwide following mass power outage just a day or two after people count, and it pretty much warms up the viewers of what else is to come.
- Seeing-eye dogs, particularly ones with breeds, fending or trying to fend for themselves. Especially as most of them aren't suitable for such a situation without humans.
- The thought that our precious friends will become vicious hunters. The notion that animals will forget you and humanity in due time. The fact that the smaller and weaker pets, such as toy breeds, will not survive along with some of the more poorly designed breeds.
- Eventually, given millions of years, there will be no trace of evidence that we humans were ever here, save for perhaps some fossils if we get so lucky. All of our achievements, all of our buildings, all of our records now lost and buried with time. Like we never existed in the first place.
- Seeing your home city being abandoned in the series combines both Nightmare Fuel and Tear Jerker.
- Prypiat, Ukraine. A ghost town which residents evacuated after the Chernobyl disaster.
- And they just HAD to add creepy child laughter in the background, too...
The Bodies Left Behind
- Mixed with a heavy amount of squick, the eventual decomposition of all human remains in general, particularly those in cryofreeze.
- Atlanta would be overrun with kudzu. However, when the kudzu dries up, it forms a tinderbox. Once lightning strikes, the kudzu ignites and burns down most of Atlanta.
The Capital Threat
- The entirety of Los Angeles being engulfed by a wildfire 10-15 years after people is really unnerving.
- This is topped by an earthquake 50 years after people that makes quick work of most of LA.
Bound and Buried
- A San Francisco cable car's cable snaps, sending it careening downhill. It goes so fast that it ploughs through a car.
Sin City Meltdown
- The fate of the Atlantic City Boardwalk. Doesn't help that it's similar to what happened to chunks of the boardwalk in Hurricane Sandy.
- The fucking abandoned amusement park in "Sin City Meltdown". Who knew that the park would have degraded so quickly after only being abandoned in 2002!
Armed and Defenseless
Road to Nowhere
- An oil refinery near Houston explodes just an HOUR after people.
Waters of Death
- The mind-blowingly slow death of a lone caiman in a zoo's water tank. It won't escape, but being a reptile it will take it more than a year to die of hunger, and this wait will be entirely in the dark because the lights will go out long before that.
- Not like the other fish fared any better. Most of them would end up choking to death once oxygen levels go down. The rest would eventually die of starvation. Keep in mind this is within a week after people.
Wrath of God
- The dead zones around nuclear power plants.
Crypt of Civilization
- The fate of the titular "Crypt of Civilization".
The Last Supper
- Abandoned supermarkets. Especially the meat and deli departments. All that rotting food is going to give nightmares...
- In addition to the simulations of rotting supermarkets, the episode also examines the real-life case of a Forth Worth, Texas grocery store that was abandoned after going bankrupt — with all the food still on the shelves. When the health department entered the building three months later, they found (among other things) jugs of spoiled milk that had literally exploded on the shelves, packages of lunch meat covered in gray slime, and clouds of flies so thick that the cleanup crew (who had to had wear hazmat suits and oxygen tanks) couldn't see more than a few inches in front of their faces.
Home Wrecked Home
- The collapse of the Burj Khalifa in Dubai.
- Salton City. A once bustling resort town turned into what could best described as "desert with a lot of trash in it".
Waves of Devastation
- Just 10 years after people, Sacramento's Folsom Dam will break and the resulting floodwaters would demolish everything in the city.
- Similarly to Sacramento, many cities in the Netherlands would end up flooded within months.
Sky's The Limit
Depths of Destruction
Take Me To Your Leader