Here is our Mighty Eagle Total Destruction video walkthrough for Angry Birds Bad Piggies level 21-4. (If you’re looking for the 3-star walkthrough video, click here.)
Blast the left tower with a Yellow bird, then fling the Orange bird into the left alley. Fire the sardine can into the chute on the left side, and make sure the bumpers are destroyed by the Eagle. If you have an alternate strategy please feel free to leave a detailed comment below.