Tenured employees shall not be dismissed or laid off except for sufficient cause, nor shall a probationary employee be dismissed or laid off prior to the written terms of an appointment except for sufficient cause. Dismissal for sufficient cause shall, in addition to the enumerated grounds contained in section 40, chapter 283, Laws of 1969 ex. sess., and RCW 28B.50.862, include but not be limited to:

(1) Any unlawful act of violence;

(2) Any unlawful act resulting in destruction of community college property;

(3) Unlawful interference with the orderly conduct of the educational process;

(4) Incompetency;

(5) Failure to perform an assignment as specified by contract;

(6) Layoff or reduction in force.