Which of the following may indicate the need for a defensive strategy in firefighting?

The indication that a defensive strategy is needed in firefighting is primarily conveyed by the situation where the building is already lost. When it becomes clear that a structure cannot be saved due to extensive damage or fire conditions, the focus shifts to protecting surrounding structures and ensuring firefighter safety rather than attempting to save the already compromised building. This approach involves establishing a defensive perimeter and using tactical measures to prevent the fire from spreading to adjacent properties or creating unsafe conditions for emergency personnel.

In contrast, active fire suppression would typically indicate that efforts are being made to control the fire and protect life and property, suggesting an offensive approach is still viable. The availability of sufficient resources would imply that there are enough personnel and equipment to mount an effective attack on the fire rather than taking a defensive stance. Successful halting of fire spread shows that firefighting efforts are currently effective and that the fire's progression is under control, which again supports an offensive strategy instead of retreating to a defensive posture.