There was a huge fire out in Montana a year or two ago. Thousands of acres, dozens of structures, on fatality. they traced it to some teens that had gone out camping. Found a receipt or something at the site, and also photos of the site posted on Facebook of their weekend.
Their campfire was too close to some bushes, and they didn’t dig out enough dirt (virgin camp site). They claimed to have doused the pit with water. The fire started a couple of days after they had left, and not much wind. The experts determined that the fire got into the roots of the nearby brush and smoldered underground until it reached the actual bush, and then it caught fire.
I have seen so much worse than that. In one instance I found the campsite of 3-4 adult bowhunters who packed up and left their fire pit smoldering heavily. There was a small creek, about 1’ across and 6”s deep, not 15 feet from the fire pit.
After drowning the fire I got in my truck and raced down the road hoping to catch up with them. I pulled into the Ranger station first to report them hoping they knew who the yahoos were. They didn’t. That gave me time to calm down which was as lucky for me as it was for them. I was a little crazy thirty years ago and they really had me fired up.
That’s not even the worst abandoned camp fire situation I’ve run across either.