Well, in 2002, a woman was lost and set a signal fire that became the Rodeo/Chediski Fire. Her fire merged with one set by a local seasonal firefighter who needed some money, and they burned 450,000 acres, the worst in Arizona's written history. Both were started on much less than 10 acres. :-)

See
http://en.wikipedia.org/wiki/Rodeo-Chediski_fire

Louise and I happened to be driving through. People in the area own animals: not just dogs and cats, but horses and cows. Getting the livestock out was a major undertaking. People were told to get out, and all the motels for miles and miles were full of refugees from the fire who didn't know if they'd have a home to go home to.

Some of the highways were so smoked in that travel was discouraged -- CB radios were very helpful getting information on whether we could get from one place to another. We also had our ham radios, which receive on emergency service frequencies, so we could monitor events and highway traffic of the fire and ambulance crews and stay out of their way.

The firefighter/arsonist got prison time, but I never found out what happened to the woman. Supposedly, she'd run out of gas and been stranded in the middle of nowhwere for a couple of days. A news helicopter covering the Rodeo fire flew around, so she set a signal fire which became the Chediski fire. C'est la vie.

Phil