earthquakes and floods
The citadel was possibly occupied by the members of the ruling classes
The Inca people are thought to possibly have started as nomadic tribes. The civilization was mainly a non-nomadic and stationary society.
The Sumerian Empire was located in Mesopotamia around the lower Tigris and Euphrates Rivers. It is long gone now. The last speakers of the language disappeared around 1 AD. Its founder was Sargon I (the great) who was quite possibly the biblical Nimrod the great hunter.
There was Ferdinand Magellan's Malay slave, Enrique. He could have possibly be the first person to sail around the world. He was probably from Sumatra and was acquired as a slave in Malacca when he was in his teens.
Most Egyptologists accept that the pyramids were all built by members of one family; 4th dynasty rulers. Khufu built the first of the pyramids, the Great Pyramid, his son Kafre built a second one (as well as possibly the Spinx), and Kafre's son Menkaure built the third. There are more esoteric theories that space aliens built the pyramids, or that survivors of the doomed Mediterranean civilization of Atlantis built them. However, these theories are largely rejected, and have the added disadvantage of being largely motivated by prejudice, and the accompanying belief that an ancient African civilization could not possibly be responsible for building one of the Seven Wonders of the Ancient World.
earthquakes and floods
earthquakes and floods
Possibly natural disaster depending on severity.
Possibly. It's unlikely that it was a Vedic\Aryan civilization.
Possibly. It can be caused by overpopulation and mismanagement of agriculture.
The citadel was possibly occupied by the members of the ruling classes
A collapse is more serious than a crisis. A crisis could be described as a problem that is so serious that it might result in a collapse if it is not handled adequately. In a financial collapse we see such things as paper currency becoming worthless, mass unemployment and possibly even mass starvation, etc.
The exact fate of the Easter Island people is still uncertain. It is believed that deforestation and unsustainable agricultural practices led to the collapse of their civilization. Some of them may have died out, while others possibly migrated to other islands in the region.
Unlikely, as the weight of snow would possibly cause the legs of the gazebo to collapse
There was more salt/solute outside of the cell, and the solute "sucks" away the water from the cell;making it shrink and possibly collapse in itself.
HIV and cholera are possibly the commonest diseases in Zimbabwe. The government has allowed the health system to collapse.
No. I don't even have any idea what you could possibly be talking about. The collapse of the Soviet Union was due to political and economic factors; fish really don't enter into the equation at all.