Sentence:  Even today range riders will come upon mummified bodies of men who attempted nothing more difficult than a twenty-mile hike and slowly lost direction , were tortured by the heat , driven mad by the constant and unfulfilled promise of the landscape , and who finally <WSD>died</WSD> . 
Meaning of the word marked with <WSD> tags:  pass from physical life and lose all bodily attributes and functions necessary to sustain life