as the forces of watson and rawdon were still active and might come to relieve the siege, marion and lee needed to bring the siege rapidly to a conclusion. at fort watson they had constructed a tower from which the attackers could fire into the fort, but this idea was not workable under the conditions at fort motte. the idea was then put forward to set fire to the buildings within the defenses. mrs. motte, apparently sympathetic to the patriot cause, provided the arrows that were used to ignite the roof of the house on may 12. when the defenders tried to go onto the roof to extinguish the flames, the attackers fired on them with their six-pound gun, driving them off. the garrison surrendered shortly after, and the americans moved quickly to put out the fires before the whole house was engulfed.