The Hessian army reported casualties of 377 killed and wounded with 20 missing or captured, while the Americans reported their losses at 14 killed and 27 wounded. Frustrated by the failure to capture Fort Mercer, Howe ordered the Hessian regiments withdrawn from New Jersey while he made plans to attack Fort Mifflin by a massive artillery bombardment. By early November the British artillery batteries on Providence Island were complete, and a number of warships were available in support. On November 10, 1777, the British opened a full-scale bombardment of Fort Mifflin which lasted for five days. Six British warships, with two small floating batteries, HMS "Vigilant" and HMS "Fury", also joined the bombardment to rake Fort Mifflin at close range. After five days, on November 15, the commanding officer of Fort Mifflin, Major Simeon Thayer, with 250 reported casualties among his 400 men and with ammunition running low, abandoned the fort that evening, leaving the American flag flying, and evacuated his men to Fort Mercer. The next morning a small party of British troops landed unopposed at deserted Fort Mifflin, hauled down the American flag, and ran up the British Union Jack atop the ruined fort. The bombardment of Fort Mifflin cost the British only a reported 13 sailors and troops killed with 24 wounded, with some damage done to some of their warships and land batteries.