chance of survival

:  something that happens unpredictably without discernible human intention or observable cause

:  the assumed impersonal purposeless determiner of unaccountable happenings :  luck

:  the fortuitous or incalculable element in existence :  contingency

:  to take place, come about, or turn out by chance :  happen

:  to have the good or bad luck

:  to come or light by chance

:  the act or fact of living or continuing longer than another person or thing

:  the continuation of life or existence

:  one that survives