To prevent the escape of the vessels up the river, Lieutenant Colonel Eyre, who commanded the division which landed on the Groton side of the harbour, had been ordered to storm fort Griswold, which had been represented to Arnold as too incomplete to make any serious resistance.

But the place being of some strength, and the approach to it difficult, Colonel Ledyard, who commanded it with a garrison of one hundred and sixty men, determined to defend it.

On his refusing to surrender, the British assaulted it on three sides, and overcoming the difficulties opposed to them, made a lodgement on the ditch and fraized work, and entered the embrasures with charged bayonets.
Further resistance being hopeless, the action ceased on the part of the Americans, and Colonel Ledyard delivered his sword to the commanding officer of the assailants.

Irritated by the obstinacy of the defence, and the loss sustained in the assault, the British officer on whom the command had devolved, tarnished the glory of victory by the inhuman use he made of it.

Instead of respecting, with the generous spirit of a soldier, the gallantry which he had subdued, he indulged the vindictive feelings which had been roused by the slaughter of his troops.