LOL, I once owned a towable back hoe.
I was once extracting a 'loosened' 45 gal sized rock and my hoe arm separated cleanly at the shoulder.
By separated I mean it broke clean off !
Close examination showed very poor weld penetration.
Actually it was an easy fix but getting it back to my shop was quite a challenge due to weight and clumsy configuration. LOL, I ended up disconnecting the hoses and dragging the arms and bucket back home on a DIY skid.
I later sold it and the buyer went on to add 7-800 hours on my weld job.