On the morning of October 27, sentries informed Magaw that Percy's troops were launching an attack supported by two frigates sailing up the Hudson. Magaw ordered an attack on the frigates, and both British ships were badly damaged by the guns from Fort Lee and Fort Washington. The frigates could not elevate their own guns to the height of the U.S. positions. The British towed away the frigates, but an artillery duel continued for some time between British and U.S. gunners.