Susan Stepney's web page https://www-users.york.ac.uk/~ss44/cyc/p/fbug.htm describes a Fortran bug urban legend, in which

when DO I = 1.100 was used instead of DO I = 1,100

Mariner I, a spacecraft bound for Venus, was lost July 22, 1962 due to a combination of hardware failure and software error, https://en.wikipedia.org/wiki/Mariner_1#Cause_of_the_malfunc... . (I misremembered this as a similar Fortran error.)