Knock Down 1 : (1) To reduce the flame and heat of a fire in order to prevent the fire's spread. (2) The initial phase of fire fighting, in which flames and heat are markedly reduced to bring the fire under control
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}