Is a supervisor liable for the actions of a subordinate?

Similarly, "[u]nder Section 1983, supervisory officials are not liable for actions of subordinates on any theory of vicarious liability." Hansen v. Black, 885 F.2d 642, 645-46 (9th Cir. 1989). However, "[a] supervisor may be liable if there exists either (1) his or her personal involvement in the constitutional deprivation, or (2) a sufficient causal connection between the supervisor's wrongful conduct and the constitutional violation." Id.