This Tactical Consideration Firefighter Research video features UL FSRI Advisory Board Member, Philadelphia Fire Commissioner Adam Thiel discussing the importance of initiating the firefight on the same level as the fire.
The quickest way to make sure conditions on the fireground get better is to put the fire out as soon as possible. This is particularly important during basement fires when the potential for crews to fall through the floor into the fire or get caught in the exhaust portion of the flowpath. Many factors can play into the initial decision of where to place the first attack line, but when possible, it is best to get water directly on the fire where it is burning.
This does not mean that the primary search is not a priority, but even more of a reason why it is important to coordinate ventilation, extinguishment and search. If the fire can be suppressed in its early stage, it can make other problems go away and it will make a better environment for potentially trapped occupants as well as our fellow firefighters.