Critical Action During Unauthorized Access Incident

As part of the safety and security protocol in a healthcare facility, the staff must adhere to an established security plan to ensure the safety of both patients and healthcare workers. During a routine safety drill, the nursing supervisor reviews the security plan and notices a section regarding how to respond to various incidents, including unauthorized access to patient areas. Which of the following actions should the nursing supervisor emphasize as the most critical in maintaining safety in the event of unauthorized access by a visitor?