The head of Tennessee’s prison system is resigning after the failed execution of Christa Pike. The announcement was made by Gov. Bill Lee on Saturday. Tennessee Department of Correction Commissioner Frank Strada said in a statement that stepping aside “is in the best interests” of the state as an independent review is carried out to determine why Pike’s execution failed Wednesday. Pike was placed on a ventilator and remained unconscious in a hospital, her attorneys said in a court filing Friday. Hospital staff, her lawyers said, were working to save Pike’s life and as of late Thursday were trying to clear the two doses of the drug that the state uses to execute prisoners.