As the War of 1812 expanded to the frontier, British-allied Sauk and other tribes began a determined effort to push out the Americans and reclaim control of the upper Mississippi. Beginning in July 1813, attacks on troops outside the fort led to another siege. Conditions were so dangerous that the bodies of soldiers killed outside the fort could not be recovered, and troops could not leave the fort to collect firewood. Outbuildings were intentionally burned by the Army to prevent them from falling into Indian hands.