Must have been the teens. Darn kids. I knew not to save when active so don't think that was it but had a number of crashes for awhile there though so wondering may have been one of those times.
I just thought they were being "quiet" for a bit as the outdoor ones were busy haunting but then went to check and noticed urns gone. Oh well at least it will be quieter for a bit.
And shouldn't affect my challenge as it wasn't something I did. LOL And for the future generations I will try and make sure they are outside when they pass.