Why I hate fire extinguishers

I had the privilege a few weeks ago to help a buddy of mine on a ranch that he is caretaker of. The guy that owns the ranch is some wealthy Arizonian who got rich doing something for cell phones. Among my duties on the ranch was the disposal of some rather large brush piles by lighting them on fire, which usually resulted in a fairly good sized bonfire. Remember I am a hick from a hick town so our size of bonfires are usually different from those of people with a more metropolitan background.
I had lit two fires that day and decided that I could handle lighting a third without to much problem. This pile was closer to a tree than most of my other fires but since we had received rain recently I thought that the tree would be fine, so I doused the pile with my diesel and gasoline mixture tossed in a match and watched the fire start. In about three seconds the flames shot up 15 feet and started licking the bottom branches of the tree. I looked at the flames under the tree and knew that I was in trouble, I could see the headlines "Man starts forest fire after accidentally lighting tree on fire." Fortunately for myself I had a fire extinguisher in my car and when the bottom branches of the tree went up in a puff of smoke I decided it was time to use it. I grabbed the extinguisher, pulled the pin, took careful aim at the burning branches and clamped down on the trigger. To my horror a puff of white powder shot out the end of the hose and landed about 3 inches from my feet. I pulled the trigger again, shook it, turned it upside down and still nothing worked. I ran swearing back to my car and grabbed a more reliable tool, the shovel.
I looked at the scene of carnage that I had created, a burning brush pile next to a burning tree, surrounded by a slow moving ring of fire supported by the dry grass and needles that kept moving further and further from the epicenter of the fire. Fortunately the tree was in meadow by itself and there was small chance of the fire jumping to other trees. I grabbed the shovel and started pounding out the flames and throwing dirt on them where possible. Let me tell you it is an interesting feeling looking your impending doom in the eye and then beating it to death with a shovel.
Eventually the fire in the tree went out leaving only a few blackened branches and a ring of ash surrounding the brush pile and tree. I stood leaning on my shovel with sweat pouring down my face and body thinking only two things; 1, how much I hate fire extinguishers and 2, that Smokey the Bear better keep his damn mouth shut.