I know towards the end of the job of draining a grain bin, people will go in there to move the grain round the edges to get it to the auger and that's when they get caught up in the moving stuff, but that's usually when the bin is near empty.
My guess is they go in there in an attempt to clear blockages.
Kubota L3010, JD 325, JD LX255, JD355D, several restored 1939 to 1952 Ford N’s
I think (not sure) that tractor rollovers have been the biggest killer over the years. I don’t farm but rent my fields out. Here in eastern PA the farmer that rents them still farms with four pre-ROPS tractors.
The problem is they get in there with the unloading auger running . Climb in top and jump in to break up a crust . Bust that layer and you may drop several feet . UNLOAD auger is running and you buried in grain .THERE IS NO CLIMBMING OUT .
One of the things I did for construction companies was mount viberators on the bottom of gravel boxes. They were about the size of a iron and 12 volt and the driver could give the load a little shake to make sure everything slid out. Would something like that work on bins