Mariner 1 and the DO Loop

I stumbled upon this interesting fact about the Mariner 1 spacecraft while browsing Wikipedia.

The Fortran DO loop caused an orbit computation error in a Mercury flight, and was long suspected to have caused the crash of the Mariner 1 space rocket on 22 July 1962 .

Mariner 1 was supposed to explore Venus but was destroyed shortly after takeoff. Its backup, Mariner 2, was successfully launched however.