My only disaster was in HO on my first layout.
I built the layout with the usual tunnel. First trip around the engine (Bachmann 4-8-4) derailed and I had to fish it out with an old cane fishing pole.
So I get the bright idea of cutting an access hole inside the mountain, easy stuff.
I run my train the next couple of days...the the engine takes a nose dive right thru the hole I made onto the concrete floor in the garage!!!
Found a crank pin had fallen out and when the side rod fell down it jack-knifed the engine over thru the hole.
This was probably back in 1978-9. I wrote Bachmann a letter and they asked me to send the engine in for repair. What I got back was a new engine, no charge!!!
My oldest grandson came over the other day and bumped into a silo I had made, crashing it to the floor. It happened in that slow motion feeling you get when things like this occur, we all saw it falling but nobody could get to it to stop it. Turns out it's no big deal, I've been wanting to replace it with something better anyway!
Scott, sorry for your loss