Alma 49:21 - 49:25
Alma 49: 21 And it came to pass that the captains of the Lamanites brought up their armies before the place of entrance, and began to contend with the Nephites, to get into their place of security; but behold, they were driven back from time to time, insomuch that they were slain with an immense slaughter.
The first assault by the Lamanites on the city of Noah was to send a large number of men at the entrance hoping that the large numbers would overwhelm the defenders. It did not work. The Lamanites were driven back with many killed.
Alma 49: 22 Now when they found that they could not obtain power over the Nephites by the pass, they began to dig down their banks of earth that they might obtain a pass to their armies, that they might have an equal chance to fight; but behold, in these attempts they were swept off by the stones and arrows which were thrown at them; and instead of filling up their ditches by pulling down the banks of earth, they were filled up in a measure with their dead and wounded bodies.
There next tactic was to try and tare down the earthen walls by using their hands. They thought if they could get into the city they could overpower the defenders. However, as they dug, the defenders on the top of the wall poured down stones and arrows on them. So instead of filling the ditch will dirt, it was filling up with Lamanite causalities.
Alma 49: 23 Thus the Nephites had all power over their enemies; and thus the Lamanites did attempt to destroy the Nephites until their chief captains were all slain; yea, and more than a thousand of the Lamanites were slain; while, on the other hand, there was not a single soul of the Nephites which was slain.
The fight continued until all the Lamanite commanders were killed and over a thousand Lamanites fighters lay dead in the ditch. The Nephites on the other hand lost not one defender.
Alma 49: 24 There were about fifty who were wounded, who had been exposed to the arrows of the Lamanites through the pass, but they were shielded by their shields, and their breastplates, and their head-plates, insomuch that their wounds were upon their legs, many of which were very severe.
Although, the Nephites had no loses by death, they did have about 50 wounded and many very severely. Their protective clothing and shields gave them great protection from the vital areas of their bodies and again as a result, there were no Nephite deaths.
Alma 49: 25 And it came to pass, that when the Lamanites saw that their chief captains were all slain they fled into the wilderness. And it came to pass that they returned to the land of Nephi, to inform their king, Amalickiah, who was a Nephite by birth, concerning their great loss.
With the loss of their commanders, the remaining Lamanites, left the city and returned to the land of Nephi where they gave a report to Amalickiah concerning their defeat.