Putting a fire "dead out" is not obvious: If it is still smoking, it is not out. If the coals are still hot, it is not out.

I use a "green stick" to turn over the burnt leftovers. I don't pour all the water on at once because that drives hot coals down into the dirt. The fire could emerge again, after you have left the area. I pour some water, and again, some more. Near the end, I hold my hand closely over the remaining coals. I pour on more water, and again, until the fire is "dead out".

Perhaps you have seen these signs in the U.S. National Forests?