In order to give the city more space I moved it up into the attic. The next day I went into the attic and saw that one of the buildings (the sand blue skyscraper; see other Gotham pages for pictures) had collapsed.
I made sure that, when the city was in its final place, all of the buildings were stable and none of them had suffered any damage.
Has this occured to anyone else? Has one of your MOC's ever just collapsed for no apparent reason?
absolutely! I've definitely experienced the same occurrence. That's why all the creations I have on here are about 6 years old, because whenever I build something decent it collapses without warning. Legos have a tendency to collapse slowly, while the connections may seem stable, after a couple hours of that annoying force gravity it can just fall over without warning.
Every now and again some connections will just fall apart in a sort of slow motion. That or it was on the edge of collapse and it was shaken to breaking point when a larger truck drove by or something.
Things like that have happened to me a few times. When I was building bionicles ( been a long time since my last creation ) they sometimes droop after a certain amount of time. What I'm trying to say is that there are weaknesses in some models, whether it be a brick error or movement error, you won't realize them until it's to late. On another note, it does give a nice touch to the place because it's one of those unique looks that aren't in other models. No two unexpected collapses are the same.