Across the Thames River in New London, Benedict Arnold was leading an 800-man detachment which destroyed stockpiles of goods and naval stores. His men set fire to a ship containing gunpowder which created an uncontrollable fire that destroyed most of New London. Meanwhile, a British force of 800 men moved toward Fort Griswold in Groton, which was garrisoned by 164 militia and local men. The British sent a flag of surrender to Fort Griswold, but Colonel William Ledyard refused and returned it. The British then attacked, opening the bloody Battle of Groton Heights. After an initial repulse, the British succeeded in entering the fort and overpowering the small garrison inside. Ledyard realized that his men were overpowered and surrendered to the British—who proceeded to slaughter the Americans and murder Ledyard with his own sword. Jonathan Rathbun described the surrender this way: