The initial fire from the mortars on shore was inaccurate, but a Signal Corps officer in Beaufort, Lieutenant William J. Andrews, acting on his own responsibility, was able to deliver messages to the battery commanders telling them how to adjust their range. After noon, virtually all shots were on target. Nineteen guns were dismounted. The walls of the fort began to crumble under the continued pounding, and in mid-afternoon Colonel White began to fear that the magazine would be breached. At 4:30 p.m., he decided that the fort could no longer hold out, so he ordered that a white flag be raised. Firing on both sides then ceased.