There's a French noir film from 1955 called Salauds-vont-en-enfer, which was released under the English title of Wicked Go To Hell. Basically, two criminals end up hiding out with a gorgeous woman on the seacoast, and of course a triangle develops with her playing them against each other. Eventually, the men end up fighting over her. Apparently, both guys drown in tidal quicksand at the end.
I haven't been able to find a clip or descent stills of the scene, except this one, which speaks for itself...

Yeah, I'd sink for her too..