Cockburn's fleet was anchored off Turkey Point, separated from Havre de Grace by an area of
shoal water too shallow for large ships to navigate. Cockburn therefore sent
Commander John Lawrence at the head of a
flotilla of sixteen or nineteen boats to row across the shoals, beginning at midnight on 3 May. Despite or because of intelligence warning of an impending attack, most of the
militia that had been in Havre de Grace had departed before the raid. Fewer than forty troops remained at the Concord Point battery when the flotilla attacked at dawn. These troops briefly returned fire until
Congreve rockets were fired at the town, which killed a resident of Havre de Grace.
Lieutenant George Augustus Westphal then stormed and captured the battery. Second Lieutenant
John O'Neill single-handedly manned another battery—the so-called "Potato Battery"—until his cannon's
recoil struck him. O'Neill retreated to fire on the British with a
musket while he unsuccessfully signaled the militia to return. The townspeople and remaining militia retreated as the British drove them further from town. Westphal and his troops entered the town and burnt 40 of its 60 houses. They spared the
Episcopal church from being burned, although they did vandalize it. Cockburn removed six cannons from the town and took O'Neill and two other Americans back to his flagship, . However, Cockburn released O'Neill upon appeal from local magistrates. Cockburn reported only one injury: Westphal was shot in the hand. After the raid on Havre de Grace, Cockburn sent troops up the Susquehanna River to destroy a depot and vessels there. British forces also navigated to nearby
Principio Furnace, a large
ironworks and cannon foundry, and destroyed the facilities there. ==Aftermath==