Broken WP Built DD Washer
I have seen similar things happen a few times on DD washers. It has usually been caused by one of several failures like, a broken basket center-post, a broken balance ring, loose suspension clamps and springs and of coarse if you drop a cinder block in the washer when it is spinning at full speed this could happen, LOL.
It is not really a big deal when you consider how many of these machines they made and how seldom anything like this happens, and I will bet you the machine was showing signs of problems that were being ignored by the user-owner before this [ JUST ] happened, LOL.