At this point Colonel Ellet ordered his rams to steam through the line of Flag Officer Davis' slower ironclads and to run down the Confederate steamers. His flagship "Queen of the West" headed straight for Colonel Lovell, the leading southern ram. A moment before the two ships crashed, one of Colonel Lovell's engines failed causing her to veer. The Union ram's reinforced prow smashed into Colonel Lovell's side, ripping a fatal hole in her hull. When Queen of the West pulled free from Lovell, she ran aground on the Arkansas shore. Meanwhile, Union ram "Monarch" crashed into foundering Lovell with a second blow which sent her to the river bottom with all but five of her crew. By then Davis' ironclads had steamed within easy range of the southern ships and began to score with the effective fire. In the ensuing close action, the Confederate River Defense Fleet was destroyed; all of its ships, except the "Van Dorn", were either captured, sunk, or grounded. Mingo and "Lioness", ordered to protect the rear of Ellet's column, reached the scene of battle after the rout was over. Memphis surrendered to Flag Officer Davis, and the pressure of relentless naval power placed another important segment of the Mississippi firmly under Union control, an open wound in the Confederate heartland. During the next few days, the rams took on cannon to prepare to fight Confederate ships which they could not reach with their deadly prows.