Spent my teen years on a farm. We were told that silos were death traps. Much like a loaded gun you had to be careful around them, respect them, or they’ll kill you. Either from falling, entrapment/engulfment, or low oxygen death.
Besides getting a void inside near the bottom that can collapse, they can also develop a false top dome that is thin, but making one think it is full.....you push on it, step on it and it collapses...dangerous stuff..