Final answer:
The incorrect statement is A: 'The secondary search is the most dangerous.' The primary search is generally more dangerous as it occurs before full fire suppression, posing higher risks to rescuers.
Step-by-step explanation:
The incorrect statement among the options provided is A: The secondary search is the most dangerous. In firefighting and rescue operations, the primary search is generally considered more dangerous because rescuers enter the structure before fire suppression has taken place, potentially exposing them to a greater number of hazards such as fire, smoke, structural collapse, and unknown environments. The team may indeed be ahead of attack lines and above the fire, as indicated in statement C. Statement B correctly describes that searching a building is typically a two-phase operation, consisting of a primary and secondary search. The primary search is aimed at quickly finding and rescuing victims in immediate danger and is done in a rapid but thorough manner, as per statement D.