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.^[11] 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.^[12] 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.^[13] 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 2 miles (3.2 km). The fort was subsequently burned.^[14]