What event led stephen decatur to burn the u. s. warship philadelphia?

The USS Philadelphia ran aground in Tripoli Harbor during the first Barbary War.

Decatur led a group of men to sneak aboard the Philadelphia and set it aflame to deny the pirates based in Tripoli the opportunity to pillage and use the Philadelphia in their attacks on merchant vessels.

First Barbary War.

Explanation:

On February 16, 1804, American naval lieutenant Stephen Decatur led a covert mission to burn the USS Philadelphia, an American ship that had fallen into Tripolitan hands, during the First Barbary War.