D+3, 18 June

When the infantrymen ashore woke the next morning, they looked out in amazement at the empty ocean and a wave of uneasy questions raced through their minds: "Where in hell are our ships? What about food and ammunition we've got to have? Will we get back the daytime naval supporting gunfire and also the star shell illumination?" The men in frontline combat had no way of knowing that over 33,000 tons of cargo had already been unloaded when the ships withdrew.

Both Marine divisions went on the attack, while the 105th Infantry joined the 165th on the far right flank, enabling Ralph Smith to put his 27th Division into motion to occupy Aslito airfield and attack along the southern coast.

That same morning, 18 June, the 4th Marine Division attack objective was the seizure of the O-3 line. This would mean reaching the east coast of Saipan and splitting in two the Japanese forces. First, however, the 23d Marines, reinforced by a battalion of the 24th Marines, had to seize the portion of the O-2 line in its zone. This was to be the division's line of departure. The entire division, with three infantry regiments abreast, jumped off at 1040. At 1340 the 25th Marines had reached O-3. The 24th Marines had tank-led Japanese counterattacks on both flanks but was able to reach O-3 before dark.

The 23d Marines, however, was stopped by intense enemy mortar and machine gun fire coming from southeast of Lake Susupe right on the boundary line between the two Marine divisions, making it unclear which division had responsibility for wiping out these enemy positions. At the same time, it was impossible to fire artillery on them for fear of hitting friendly troops. As a result, the 23d Marines suffered heavy casualties. So, by the end of the day, although all of the 4th Marine Division's regiments were in contact, a gap still existed between the two Marine divisions.

The bizarre becomes common place in combat. For instance, one of the 23d Marines' 75mm half-tracks fired into a Japanese cave that day, and a dense cloud of noxious fumes came pouring out. A gas alarm was sounded. This meant serious trouble, for all the riflemen had long since jettisoned their burdensome gas masks. Relief flooded through the men as it was established that the fumes were not poisonous and came from picric acid the Japanese had stored in the cave.

Over in the 2d Division's zone, the 8th Marines saw some bitter fighting over Hill 240. A heavily defended coconut grove required saturation fire from the artillery of the 10th Marines before the riflemen could smash their way in and clean out the grove.

The price for the two Marine divisions had been heavy. By the night of D+3 they had been bled by more than 5,000 casualties.