The missing submarine carrying five rich guys to the depths of the Titanic's wreckage, and now likely to their deaths, has become the biggest news story of the year. By now, the submersible's estimated oxygen supply would be gone, but that might not matter. That's because in all likelihood, the sub lost contact with its surface ship due to a failure in structural integrity, and an instant implosion from water pressure above. 

But what might that look like? Compared to the all too common explosion, implosions can be hard for us surface dwellers to visualize. If you feel this way, then the destruction of old train cars using vacuum induced implosion has you covered. 

"Apparently at that depth, if it’s minivan sized, it would implode to about the size of a basketball," serena.illescas commented. 

That's because these train cars are being imploded by one singular atmosphere's difference in pressure. The submarine would be under about 380. 

On the bright side, it would be a much better way to go than slowly running out of air, contemplating your impending doom.

As samiesocal commented, "At this point, this would be BEST case scenario."