a Shawnee ambush on Major Thomas Van Horne's 200 men, who had been sent to support the American supply convoy. Half of Horne's troops had been killed. Hull had also faced a lack of support from his officers and fear among his troops of a possible massacre by unfriendly indigenous forces. A group of 600 troops led by Lieutenant Colonel James Miller remained in Canada, attempting to supply the American position in the Sandwich area, with little success. Major General Isaac Brock believed that he should take bold measures to calm the settler population in Canada and to convince the tribes that Britain was strong. He moved to Amherstburg near the western end of Lake Erie with reinforcements and attacked Detroit, using Fort Malden as his stronghold. Hull feared that the British possessed superior numbers; also Fort Detroit lacked adequate gunpowder and cannonballs to withstand a long siege. He agreed to surrender on 16 August, saving his 2,500 soldiers and 700 civilians from "the horrors of an Indian massacre", as he wrote. Hull also ordered the evacuation of Fort Dearborn (Chicago) to Fort Wayne, but Potawatomi warriors ambushed them, escorted them back to the fort where they were massacred on 15 August after they had travelled only . The fort was subsequently burned. Brock moved to the eastern end of Lake Erie, where American General Stephen Van Rensselaer was attempting a second invasion. The Americans attempted an attack across the Niagara River on 13 October, but they were defeated at Queenston Heights. However, Brock was killed during the battle and British leadership suffered after his death. American General Henry Dearborn made a final attempt to advance north from Lake Champlain, but his militia refused to go beyond American territory. American Northwest, 1813 After Hull surrendered Detroit, General William Henry Harrison took command of the American Army of the Northwest. He set out to retake the city, which was now defended by Colonel Henry Procter and Tecumseh. A detachment of Harrison's army was defeated at Frenchtown along the River Raisin on 22 January 1813. Procter left the prisoners with an inadequate guard and his Potawatomie allies killed and scalped 60 captive Americans. The defeat ended Harrison's campaign against Detroit, but "Remember the River Raisin!" became a rallying cry for the Americans. In May 1813, Procter and Tecumseh set siege to Fort Meigs in northwestern Ohio. Tecumseh's fighters ambushed American reinforcements who