When can a manager of an apartment complex change the locks?

In Canada if there has been several break-ins in the complex then the landlord has the right to change ALL locks, but the tenants must be notified and given a new key. The only other reason would be if the tenant has not paid their rent, then the landlord can change the lock on that particular apartment with the contents still in it until the tenant pays the rent. In the US a landlord cannot use self-help to hold the renter's personal property for rent due, unless it was so stated in the rental agreement. Before a landlord can seize property and lock a delinquent tenant out of the residence they must use due process of law, receive a Writ of Possession and serve the delinquent tenant with the writ. If the tenant does not recover his or her belongings within the specified time limit, the landlord can consider them abandoned and dispose of them in whatever manner chosen. If the landlord wishes to remove the property from the residence before the set time expires he must secure those items in a storage area.