Give 10 days writen notice, try all possible means to contact th

Then, you can start action. It is recommended to have abandoment in your lease contract. something like this.

ABANDONMENT: If Resident leaves said premises unoccupied for 15 days while rent is due and unpaid, Owner is granted the right hereunder to take immediate possession thereof and to exclude Resident there from; removing all his/her property contained therein and placing it into storage at Resident’s expense.