Gen. Beauregard arrived at Johnston's headquarters at Bowling Green on February 4, 1862, and was given overall command of Polk's force at the western end of Johnston's line at Columbus, Kentucky. On February 6, 1862, Union Navy gunboats quickly reduced the defenses of ill-sited Fort Henry, inflicting 21 casualties on the small remaining Confederate force. Brig. Gen. Lloyd Tilghman surrendered the 94 remaining officers and men of his approximately 3,000-man force which had not been sent to Fort Donelson before U.S. Grant's force could even take up their positions. Johnston knew he could be trapped at Bowling Green if Fort Donelson fell, so he moved his force to Nashville, the capital of Tennessee and an increasingly important Confederate industrial center, beginning on February 11, 1862.