Disasters are events that occur randomly during the game and pose a special threat to the player and its cubs.
Forest fire
Sometimes a bolt of lightning will strike in the player's vicinity, this will start a fire. To survive, the player must evade the flames and exit the area. The flames last about one or two minutes and then are extinguished by rain.
If it traps you with no escape, you will lose one of your cubs.
I suggest not to panic, as if you run into a corner or lose your stamina you will loose a cub. Instead, carry on like normal, navigating your way out of the flames and to an open area. The flames only seem to happen in heavily forested areas, so once you reach the plains you will be safe.
The Lonesome Fog
In the lake and den area there may appear a huge black cloud that covers some most of the map, including the islands. When this happens, the music will change, and the sky will darken. When at the lake, to escape the fog you must travel as far uphill as you can, or leave the area entirely. When in the den area, the fog will spawn in the forested parts of the map. Head to your den and wait until it passes. If you head into the fog, you risk losing your cubs. Often a cub will freeze up and cry out. When this happens, you must pick the cub up and carry it. If you don't, the cub will remain frozen, and if you get too far from it, you will hear barking and you will lose your cub. This is likely a wolf taking your cub into the fog. When you find yourself incapable of escaping the fog, sit down and wait for it to recede. If a cub wanders out of your sight, and you can't find them consider them dead. The fog also has a cousin in the mountains, though it doesn't have a confirmed name just yet. Unlike the fog, it will spread everywhere, and you have to wait until it disappears.