Tzitzit: All or nothing

Hi,

For the tzitzit on a garment to be valid, one must have the strings on all four corners; all of the strings combine for one overarching mitzvah. If the strings on any corner become invalid, the entire set of tzitzit are invalid.

(Shulchan Aruch Orach Chaim 13:1; Mishneh Berurah 13:1)

Have a great day,
Mordechai