In the early fall of 1777, events did not fare well for George Washington’s army in Pennsylvania. Defeats at Brandywine and Paoli enabled William Howe’s forces to occupy Philadelphia unopposed on September 26. To regain the initiative, Washington and his lieutenants plotted a bold strike against the primary British camp at Germantown, about five miles north of Philadelphia. In the early hours of October 4, the Americans moved toward their target in four columns with the intent to strike as one at 5 a.m. Not all columns were in place at the appointed hour and others were spotted by British sentries who fired warning shots to awaken the camp. American advancement was slowed for more than an hour on one front when several dozen British soldiers took refuge in a private mansion, Cliveden, owned by the Pennsylvania chief justice. The mansion's stout stone walls enabled the defenders to hold out against an artillery barrage delivered by Henry Knox's forces. The British were reluctant to surrender, fearing reprisals from the Americans for the recent “massacre” at Paoli. A heavy fog, combined with smoke on the battlefield, caused confusion among the American ranks, including incidents when soldiers fired on their own with deadly effect. Small numbers of Patriot troops managed to fight their way into Germantown, but the others' failure to join them necessitated a pullback. Once again, Nathanael Greene provided distinguished service by organizing the overall retreat. As the Americans pushed northward, they were harassed by British snipers who continued to take a heavy toll. Nevertheless, Howe once again failed to seek a knockout blow by pursuing his enemy in force. The Americans suffered more than 700 casualties at Germantown, in addition to 400 soldiers captured. The British lost more than 530 men.