After seeing this story on another TV station, it occurred to me that "knocked down" in fire parlance means starving oxygen or damping flame length, so technically it wouldn't require water. Tho I note also that a 'firehose' weather event has 'knocked down' an avalanche or two...

Crews may have "knocked down" the fire but I'll bet it wasn't with water. Sodium is very volatile unless as a safe compound; it will burn if exposed to oxygen (which is in water- H 2 O). So the rote reporting works for now, but could get interesting later (if anybody gets any news Facts out of this).