First things first, complete economic collapse brings civil disorder, all supermarkets would be cleaned out in less than a day. If you are not prepared with a safe house in the country where there is plenty of food and water, you will most certainly have a markedly reduced survival rate.
Mass looting and criminality, violence in the streets and of private property would ensue in all metropolitan areas, and there would not be any place to hide from the angry mobs pillaging.
Immediately after mass civil disorder breaks out, all mobile/cell phone services would be cut by the government and there would not be any internet or telephone. This is why if you are organised, you should have already invested in a radio system.
During civil unrest, there are no hospitals, utilities, fire service, police force, doctors, financial services or lawyers.
Depending on the severity of the crisis, you and your family should prepare for as long as it takes before order is restored. This could be from six months to five years or more. The state of martial law could easily escalate to civil war which could take longer to die down.
In the event of martial law, civilians could possibly be rounded up by paramilitary and government forces and put into camps, if you are well prepared you will not be one of these people. Do not depend on the government for your survival or anything. You must be self sufficient, and most of all do not trust anyone, or be careless with speech. In times of chaos, a careless word to anyone could mean your immediate or eventual demise.