In retreat you destroy stuff so the enemy can't use it, but...

To a good artilleryman, it seemed almost sacrilegious to destroy the guns he had so lovingly fussed over for years. As they smashed the breechblocks and destroyed the dial sights, many were openly crying.

Walter Lord, The Miracle of Dunkirk (New York: Open Road Integrated Media, 2012), p. 54 (copyright 1982)