german soldiers would usually cross ANY bridge without being in step .
the command was : "OHNE TRITT , MARSCH ! " .
even strong bridges can be endangered by many people "marching in step" across it , i believe .
hbg
bridge built across the ELBE river at hamburg under napoleon's reign - he wasn't all bad !
btw it's been replaced in the meantime , but it took napeleon to have the first bridge built !