The first attack on the city occurred on April 13 and was preceded by a powerful artillery barrage. The PAVN captured several hills to the north and penetrated the northern portion of the city held by the 8th Regiment and 3rd Ranger Group. ARVN soldiers were not accustomed to dealing with tanks, but early success with the M72 LAW, including efforts by teenaged members of the PSDF, went a long way to helping the overall effort. The 5th Division commander, General Hung, later ordered tank-destroying teams be formed by each battalion, which included PSDF members who knew the local terrain and could help identify strategic locations to ambush tanks. They took advantage of the fact that the PAVN forces, who were not used to working with tanks, often let the tanks get separated from their infantry by driving through ARVN defensive positions. At that point, all alone inside ARVN lines, they were vulnerable to being singled out by tank-destroying teams.