"Just cause" may consist of any one or more of the following:

(1) incompetence; (2) wilful neglect of duty; (3) wilful violation of the rules and regulations of the State Board of Education; (4) unprofessional conduct; (5) drunkenness; (6) cruelty; (7) crime against the law of this State or the United States; (8) immorality; (9) any conduct involving moral turpitude; (10) dishonesty; (11) evident unfitness for position for which employed; (12) sale or possession of narcotics; or (13) breach of contract.