See map here: https://www.ww2history.eu/from-d-day-to-paris/3668-d-day-plus-50-55.html
A Canadian diversionary attack southeast from Caen on July 25th had drawn German reserves into a major counterattack, while carpet bombing south of Saint-Lô with more than 4,200 tons of munitions stunned the Germans in that sector.
After a day of hard fighting, the German line crumpled, and American armored columns pushed through the wreckage at an ever-accelerating pace.
Coutances fell on the 28th and Avranches on the 30th.