The two lines of this verse mean the same thing, which of course is common in Hebrew poetry. Good News Translation, which does not use poetic format here, combines the two occurrences of they perished. Translators using poetic format will probably want to find an effective repetition. The reference is to the race of giants “dying out,” an appropriate expression in English which Good News Translation uses. It means a gradual disappearance, not a sudden extinction. For translations that keep the poetic format, the second line may be translated “They died out because they were too foolish to survive.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on The Shorter Books of the Deuterocanon. (UBS Helps for Translators). New York: UBS, 2006. For this and other handbooks for translators see here.