Why the liquid nitrogen is not helping to extinguish the fire

Firstly there is a typical Ukrainian problems. Equipment was fully depreciated and the leadership is completely incompetent (November 15, 2010 Sergei Smolanov, rescue service chief, was arrested for financial fraud in the purchase of equipment).
It should be noted that at very high fire technological problems arise with the use of liquid nitrogen. If the liquid nitrogen does not get submitted to the center of the flame, it evaporates little impact on fire. And nitrogen gas weighs about as air, so it displaces the weakly reactive gases.