Some cities, like Mohenjo-Daro, had high walls. These walls had gateways so people could come and go .Over time houses were built on top of houses
over time the river would flood and destroy the farmlands and the salt effcted the soil so the crops could not grow
The indus people used seals to label thing such as a bag of grain someone owend most of the seals had pictures of amnials on them most of the time it was a goat but sometimes other anmials were on it
Keeping clean in the indus river civalstion to bathe and take showers people would take big jars and poor them over there head then the dirty water would go into the drain through the pipes and out into the street
Many people believe that the great bath was used for people that had simlar belifes about purity
there are many ways the indus civalastion could have come to a end but i believe that it ended because of a lack of food and water also because the flooding of the river could damage the crops