3 Nephi 4:11

and the battle commenced in this the sixth month; and great and terrible was the battle thereof; yea, great and terrible was the slaughter thereof, insomuch that there never was known so great a slaughter among all the people of Lehi since he left Jerusalem.

The battle started in the sixth month. It was a terrible battle. Many people were killed. There had never been such a big killing among all of Lehi’s people since he left Jerusalem.

The battle began in that sixth month. It was brutal and terrible. The slaughter was worse than anything the people of Lehi had ever seen since leaving Jerusalem.