In any industry in California, a wrongful termination can come about for a number of reasons. For example, individuals could be fired based on their race or their gender. It is not legal for employers to discriminate on the basis of either of these things, along with sexual orientation, age, disabilities and more.
On top of that, an employee could be wrongfully fired from his or her position if the employer asks the employee to do something that is illegal and the employee refuses. If the employer then retaliates by firing the individual from the job, based on nothing but the employee's adherence to the law, the employer has broken the law.