21. FROM 1800, 10 MAR 45 TO 1800, 11 MAR 45 (D PLUS 20) (a) Enemy activity was relatively quiet along the entire front. Some infiltration attempts were made on the front of RCT 25. The area of resistance by- passed in 184 N was contained by elements of this RCT. It was quite apparent that the main enemy resistance had been broken but that the Japanese were continuing their passive defense from an intricate system of well concealed caves. These caves were hard to locate and were generally disclosed only when the enemy opened fire. Two (2) DD's provided illumination for the Division throughout the night. (b) The Division continued the attack at King-hour minus 60, King-hour being 0830, in accordance with VAC LANFOR Order No. 18-45, without a preliminary artillery or naval gunfire preparation, to assist in the completion of the capture of IWO JIMA. Formation and boundaries - no change; Line of Departure - front lines at King-hour. (c) RCT 23, with BLT's 2/23 and 3/24 abreast, continued the attack at King-hour minus 60 and rapidly overran the weak enemy resistance to its front by employing combat patrols to cover all of the beach areas. On the left of the RCT zone, the mopping up could not be completed because RCT 9 of the 3d Division was operating along the boundary and in the zone of action of RCT 23. On the right, BLT 3/24 encountered strong enemy resistance in the vicinity of TA 185 K. This resistance was reduced by the end of the period, and combat patrols had cleared out the remainder of this zone. BLT's 1/23 and 3/23, in RCT Reserve, were employed in mopping up the rear area. At 1530 BLT 1/23 relieved BLT 2/23 in its zone, completing the relief by 1700. (d) RCT 25, with BLT's 3/25, 2/25, and 2/24 in line from left to right, continued the attack at 0745, fifteen (15) minutes late, to execute the mission assigned. BLT 1/25 neutralized the enemy resistance in TA 814N by 1100. Shortly after the assault was initiated, the left of the line received intense fire from rockets, mortars, and small arms. The center of this fire area was located as being in the vicinity of TA 185 PQV, and it was at once apparent that this area was the final defensive position of the enemy in this zone. The terrain in this area was not normal in any respect; it could be classified only as a terrain freak of nature. However, it was well suited for the construction of cave positions, and the Japanese had utilized this advantage to the fullest extent. Their scheme of maneuver was to hold up the advance as long as it was possible, and to inflict as many casualties as they could before they were forced to adopt their usual suicidal tactics. By the end of the period this resistance in the above TA had not been liquidated. The Division Reconnaissance Company continued mopping up operations in the rear area. (e) RCT 24, less three (3) BLT's, had no change. BLT 1/24 was in VAC LANFOR Reserve. (f) 4th Provisional Battalion. One (1) platoon was attached to the Pioneer Battalion for the defense of Beach Blue 1 during the hours of darkness. The Battalion continued mopping up operations in the rear areas of the Division zone. (g) 14th Marines. In accordance with VAC LANFOR Order, 2/14, 3/14 and 4/14 fired a thirty (30) minute preparation from King-hour minus 10 to King- hour plus 20 in the zone of the 5th Marine Division. 1/14 was in direct support of the Division until 1430, when it was directed to reinforce the 13th Marines. VMO-4 fired one (1) mission during the period and executed surveillance of fires in the Division zone. Artillery spot missions were secured at 1145. No targets were reported by sound ranging. The total number of missions fired in the 4th Division zone was eleven (11); the total in support of 5th Division was twenty-six (26). (h) 4th Tank Battalion. AT the end of the period, thirty-nine (39) tanks were operational, four (4) were damaged, and eleven (11) were destroyed. During the afternoon one (1) flame thrower tank with crew was loaned to the 3d Marine Division. (i) Aviation. VMO-4 flew nine (9) tactical observation missions. One (1) plane was hit by enemy machine gun fire, and at the end of the period one (1) plane was operational. (j) Naval Gunfire. No fires were placed in the Division zoned during the day. One (1) DD was on call for possible emergency missions. (k) 4th Engineer Battalion. Company "A" was attached to RCT 25, Company "B" to RCT 24, and Company "C" to RCT 23. All units continued the execution of demolitions and road work in the areas of these respective RCT's. (l) 4th Pioneer Battalion. No change in assignment. (m) Combat efficiency was reduced to an estimated 38%. (n) Weather and Visibility. The weather was fair, visibility unlimited, and ceiling overcast 2/10 to 8/10.