If an event occurs that may interfere with the safe passage of trains, what is the first action employees must take?

In situations where an event may interfere with the safe passage of trains, the immediate priority is ensuring the safety of both personnel and the trains. Attempting to stop trains via radio communication is crucial as it swiftly alerts train operators about the potential hazard, allowing them to take preventive measures to avoid accidents. This proactive approach is vital in reducing risk and ensuring the safety of all involved.

Other actions, while important, serve as secondary responses. Evacuating the area is essential for safety but does not directly prevent trains from being in danger. Providing flag protection is crucial, but it comes after the immediate need to halt any train movement. Notifying the Supervisory Officer is important for follow-up actions, but it is not the first step, as immediate intervention with communication can directly prevent potential disasters.