Major General Mansfield Lovell, Commander of Department 1, Louisiana, was left with one tenable option after the Union Navy broke through the Confederate ring of fortifications and defense vessels guarding the lower Mississippi: evacuation. The inner ring of fortifications at Chalmette was only intended to resist ground troops; few of the gun batteries were aimed toward the river. Most of the artillery, ammunition, troops, and vessels in the area were committed to the Jackson/St. Phillips position. Once this defense was breached, there remained to face Union troops and warships only three thousand militiamen with sundry military supplies and armed with shotguns. The city itself was a poor position to defend against a hostile fleet. With high water outside the levees, Union ships were elevated above the city and able to fire down into the streets and buildings below. Besides the ever-present danger of weather-caused breaks in the levees, now an even greater threat to New Orleans was the ability of the Union military to cause a break in a major levee that would lead to flooding most of the city, possibly destroying it within a day.