One of the working theories is that hot exhaust + tall grass.
The area received good rain last year which yielded a good grass crop. Now that tall grass is dead grass and it’s been very dry this year so far.
100% human caused.
The plains and forests used to burn like this, unchecked, before western civilization. Whether it was lightning then or human caused now, the prairie WANTS to burn. And it should. It’s ecology.
If we want to co-habitats with the natural world we need to do more prescribed fire/ controlled burns and manage naturally caused fires instead of extinguishing them as fast as possible. There’s going to be a balance. If we try to interrupt nature she will hit us harder. Nature is dependent on fire and we should get over it. If we aren’t proactive about Fire we will continue to get these kinds of fires.