Low Water Supply

Suddenly water supply in my home becomes very bad. I am not sure this is because of too many people are using water at the same time in our apartment or because the management has cut off water supply too our unit. It is very unusually to have such bad water supply. Water supply started super bad since this morning but still not as worst as now! Now is just like no water from tap. Lucky we still have tank water for bath; if not I think we have to take bath at my mother home already.