In 1747 and 1751, Løgstør was ravaged by violent fires, and in these difficulties the population declined, so that in 1769 the city had only 392 inhabitants.
I 1747 og 1751 var Løgstør hærget af voldsomme ildebrande, og oven i disse vanskeligheder faldt folketallet, så byen i 1769 kun havde 392 indbyggere .