4. Method of Assault

It is necessary to employ all weapons possible in the preparatory fires in order that troops gain a foothold in a fortified building. High-angle artillery and mortar fire prove worthless against buildings of this type. Direct fire, high velocity, self-propelled guns, like tank destroyers, M-7's, and tanks prove effective only after hours of shelling have literally torn the building asunder. Direct fire with l05mm howitzers is useless. However, the l05mm howitzer on carriage M7 may be used to enlarge the cracks created by 76mm tank destroyer guns. During all shelling, the enemy either will move to elaborate previously prepared tunnels in the basement or at least away from the outside defenses so that our troops may move in. Preparatory fires should be as intense as possible to disorganize and shock the fanatical enemy. A building of more than one floor is often untenable if the enemy holds the upper floors, even though our troops are inside. Therefore, the best method of using the direct fire weapons is to pound the roof and top floors first and work the fire down to the basement and ground floor, thus placing our troops on equal terms with the enemy insofar as elevation is concerned. However, if the intention is to demolish the building completely, the direct fire weapons should be employed on the ground floors first. This will prevent the debris and rubble from falling on and forming a large pillbox on the lower floors. The use of artillery at direct fire ranges involves considerable risk from enemy small arms. Service of the piece precludes use of even the light protection afforded by the gun shield, therefore firing positions must be cleared of snipers before the artillery is brought in.

After the assault guns have completed their preparatory fires, heavy fire should be continued from machine guns and rifles placed in adjoining buildings. Smoke must be placed on any adjacent enemy positions capable of firing on the friendly assault units. The enemy will immediately attempt to rf!man his guns in the building under attack, and this necessitates moving troops very rapidly into the building. Once committed to the assault, troops must not falter. Embrasures caused by our weapons should be used as points of entry rather than normal entrances, which will be covered by fire. The number of casualties will be reduced if, when moving into a Jap occupied building, the attacking units deliver fire from the beginning of the attack even though no enemy fire is received initially. At times the enemy permitted our troops to enter a building, and held their fire until our troops were entering corridors or other exposed places. Also the Japanese frequently dropped grenades from stories above the ground floor. Our troops found that by firing continuously as they moved forward, the enemy tended to open fire sooner and thus enable friendly units to locate his position. This type of fire also greatly reduced the accuracy of enemy return fire.

Inside the building, the attackers should bring corridors, windows, doorways, or other likely sources of enemy resistance under fire as soon as possible. When the first corridor or section of rooms are taken, additional troops should be committed at once. Speed is essential and as soon as a stairway is secured these troops should advance to the upper floors, allowing no time for the enemy to recover. Attackers should get into the highest floor possible immediately either by going up stairs or directly up the walls, since once the upper floors are under control, the remaining enemy can be eliminated much easier. A point to stress-go into the buiding firing. The enemy is usually badly dazed by our tremendous fire power and by continuing heavy fire at possible positions. By using grenades in closets, fortifications, and rooms or hallways before entering, the assault units can further upset the enemy and prevent him from getting set for the close-in fighting. Rocket launchers or rifle grenades can be used to fire on positions which cannot be reached by hand grenades. The troops on the lower floor should continue to eliminate all resistance encountered. Guards should be left covering all holIes and pillboxes suspected of having an underground entrance. Holes and pillboxes should be burned out by flame throwers and then covered, and small parties should be organized to search the building thoroughly, checking debris, holes, and all possible hiding places. In one instance, a large number of Japanese were driven to the basement of a large building. Friendly troops held the balance of the building. Flame throwers and grenades were employed through holes which engineers blew in the floor and the enemy was annihilated without loss to our troops. In attacking buildings and fighting inside, it is important that only sufficient men be assigned to a single assault mission. A small, well-trained unit can take an objective of this type more efficiently than a force which is so large as to cause confusion among the troops. A platoon can often establish a foothold in all except very large buildings. However, this unit should be followed closely by another unit so as to take full advantage of any favorable situation or to counteract any unfavorable one which may have arisen.

The fight for a large fortified building may go on for days, with troops fighting from corridor to corridor and room to room. At night a defensive perimeter must be thrown around the building if at all possible or the enemy will reinforce from the outside. The perimeter system must be organized within the building as well, else the enemy will reoccupy by night the favorable positions he lost during the day.

5. Mine Removal

Most of the mines found were improvised from depth bombs, high explosive shells, and aerial bombs. The technical problem of disarming was less difficult than the tactical problem of removing them from fire-swept areas. Among the several methods employed, one of the most effective in the South Manila area was as follows:

Infantry occupied the ruins of each side of the street to prevent close-in rifle fire. A tow cable was attached to the front of a tank. With four engineers behind the tank it proceeded along the street toward the mine field, firing machine guns and cannon at the enemy positions. When the mines were reached, the tank stopped its cannon fire but continued with machine gun fire. One engineer ran forward to the nearest mine, disarmed it, and after attaching the tow cable, dashed back to the rear of the tank. The tank, continuing fire, pulled out the mine by backing away. The routine was continued, using alternate engineers, until the field was cleared. The tank and infantry then advanced to new positions. A well-qualified mine removal man can accomplish the disarming and removal in ten to fifteen seconds, and the Japanese do not seem to be able to direct their fire on a man in that length of time.

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