[in_vino_vomitus]

Don't think I've ever had them drop dead for no reason, but I've had them killed off by leaving them at their station during a DC attack. I also tend to find that games saved in proximity to a convoy won't reload. If you're in the habit of overwriting a current game's save file, then i would stop doing that for OM

Still worth all of the grief to play it though - it's my favourite of all the supermods