Which action is crucial when a malfunction occurs in an elevator?

Notifying the building manager is essential when a malfunction occurs in an elevator because the building manager has the authority and responsibility to take appropriate action in response to safety concerns. They can assess the situation, coordinate repairs with qualified personnel, and ensure that safety protocols are followed.

Immediate repair might seem like a priority, but without proper assessment, rushing into repairs could lead to safety hazards. Pressing the service button is a helpful action for immediate safety measurements, but it does not initiate the critical processes needed to handle the malfunction effectively. Ignoring the issue until the next scheduled maintenance poses a significant risk to the safety of the elevator users and could lead to further complications or accidents. Therefore, informing the building manager is the most prudent first step in handling an elevator malfunction.