Indus civilization : a mystery important to know.

Indus valley civilization makes a huge mystery because of it's cultural development. And science development, economic development and well developed social system and also art and architectural development in really past era. Nobody knows how long time it will take to develop at this level. I think it would take a really long time to develop at this level.
How it destroyed it's really big and biggest mystery for present human civilization. Because to know about this can help to save our modern civilization.
The people of indus....... were tread world wide ( i only mean country to country), that make sense of their development. It also proves that they have a good transport system also. They are know about cotton fabric. Their agriculture system was also developed, they were cultivate wheat also. Political development tells a lot about harappan or Indus valley civilization.
Concussion :- to know that how to Indus valley civilization destroyed. Even they are fully developed really important. Because that information can help to save our modern civilization to being destroyed.

Thank you very much