Under the AAMVA CDL Manual, in which of these situations MUST a driver evacuate the school bus?

AAMVA CDL Manual, Section 10.3.1 – Planning for Emergencies (Mandatory Evacuations), p. 10-6

A bus stalled on tracks can be struck by a train with little or no warning. This is one of only five situations the manual treats as leaving no room for judgment calls — evacuation is required, not optional.