So, you're listening to the little fire up on the hillside. It's all nice and "routine" as the dozers start the line and the two tankers orbiting are itching to drop their loads but waiting for the right moment, which doesn't look like it will happen with this wimpy fire. The ground units are just about finishing up the flanks and "pounding" the final line around the front of the fire. Just 100 yards of line to go. The wind is out of the east and pretty steady at 5mph
On the other side of the ranger unit a fire lookout gives the 1400 hour lookout check; the wind reported at 20mph from the north, exactly 90 degrees direction change then it was 5 minutes ago. The battalion chief at the scene of the fire hears the wind change and double checks his own weather report he conducted 10 minutes ago. "North Wind" and fire can cause lots of trouble around here.
Over the handitalkie..."Engine 2581 IC, lets double time on the scratchline. Wind change coming up"
The fire fighters scramble with handtools to finish the 100yrd scratchline, a task they have practiced over and over in training. Active flame only 20 yards away. Between them, some scrub oak and tall grass, candy to a fire. They decide to backfire while the wind is on their side to help the puny scratchline hold up against the larger inferno coming towards it. Suddenly the smoke lingers in the air - almost dancing in the air as it tries to make up its mind where to go. The battalion chief's clipboard of papers shuffle on the side that isn't clipped down. He looks up and sees the smoke dance also - in lingo, waiting. He knows very well what will happen in the next 10 minutes.
The firefighters on the ground quickly bless the pink "mud" as it settles on the ground between them and the fire. They continue the scratchline - unknowning the wind has already shifted and the flank they are working on soon becomes the head. The firefighters scramble away from the scratchline advising the IC and requesting two more engines to roll up for mobile attack before they lose the line.
Too late, the flames find some tall grass under a tree, a spot where the pink mud couldn't reach the ground. Somehow the flames communicate to the rest of the fire that it found a hole in the wall and soon, the entire incident seems to squeeze through and bust into the open field - 30 yards away from the nearest engine. Air Attack quickly sets the helitack copter on the breakout while it decides how to strategically use the sole S2 Grumman, a load enough to only put a candle out in these conditions. He decides to wait until structures or lives are threatened. Dispatcher at ECC is sitting watching the noon news with her feet propped up near the radio. Almost disturbed from the peace she takes the order from Air Attack for 5 more tankers and 2 copters. She takes the order and then calls IC, the tone in her voice showing her curiousness to the aircraft order. No answer, try again with more urgency in her voice as her hand hits the TV mute button.
The IC on the ground packs up and moves to the new breakout to take in the scenario. Those 20mph winds hit all too soon. The fire is racing up the hill, a subdivison silently nestled in the trees a quarter mile away and a school - still in session, sits off to the south, also a quarter of a mile away. IC hears ECC calling and begins the order of what he needs, updating the incident from 5 acres to 50-60 acres rapid rate of spread. Requesting 4 strike teams of structure protection engines, 5 crews, 2 more dozers and 5 water tenders. By now, the TV in the ECC is off, and all peace is broken by both the Red Phone and 911 phones. Neighbors start reporting the conflagaration, North Ops wants answers - now.
The Incident Commander looks down at his map, looks up through the trees and spots the school. He silently prays for the safety of all and after his quick sigh is done, he calls half the engines off the line to race to the school. He races to the school himself and finds the school office. The wind whips the office door out of his hand and slams it against the outside wall, announcing his dirty, smoky, yellow-suited presence to the office. He gets on the radio, orders a command net, incident command team, sheriff dept for evacuations, and 10 strike teams. He declares a major incident as the fire tops 150 acres in 5 minutes as it races up the hill. Through the howling wind the school secretary could just make out the final words that would start the beginning of a 2 week catastropohic fire..."I want this school empty and shutdown in 10 minutes"
(not based on any particular incident - just an imagination)