S.D. Codified Laws § 15-6-63

If by reason of death, sickness, or other disability or separation from office, a judge before whom an action has been tried is unable to perform the duties to be by him performed after a verdict is returned or findings of fact and conclusions of law are filed, then any other judge regularly sitting in or assigned to the court in which the action was tried may perform those duties; but if such other judge is satisfied that he cannot perform those duties because he did not preside at the trial or for any other reason, he may, in his discretion, grant a new trial.