burned all the palm trees on the beach and destroyed every building that could be seen. Experience gained by the Japanese from the invasion of Saipan was used to try to mitigate the effects of the bombardment. Despite this, the bombardment far exceeded the expectations of the defending forces which were dug in along the coast as they were on Saipan. Many of the bases and guard towers were also destroyed. However, artillery pieces entrenched in dense forests, caves, trenches and locations four kilometers or more from the coast were able to escape destruction and became a source of heavy Japanese resistance. Guam, ringed by reefs, cliffs, and heavy surf, presents a formidable challenge for any attacker. Underwater demolition teams reconnoitered the beaches and removed obstacles from 14 to 17 July. Despite the obstacles, on 21 July, the American forces landed on both sides of the Orote Peninsula on the western side of Guam, planning to secure Apra Harbor. The 3rd Marine Division landed at Asan near Agana to the north of Orote at 08:29, and the 1st Provisional Marine Brigade landed near Agat to the south. Japanese artillery sank 30 U.S. LVTs and inflicted heavy casualties on the landing troops, especially of the 1st Provisional Marine Brigade, but by 09:00 marines and tanks were ashore at both beaches. By nightfall, the Marines and soldiers of the 77th Infantry Division had established beachheads about deep. Japanese counterattacks were made throughout the first few days of the battle, mostly at night, using infiltration tactics. The Japanese penetrated the American defenses several times but were driven back with heavy losses of men and equipment. The U.S. Army's 77th Infantry Division had a more difficult landing on 23–24 July. Lacking amphibious vehicles, they had to wade ashore from the edge of the reef where the landing craft dropped them off. The men stationed in the two beachheads were pinned down by heavy Japanese fire, making initial progress inland quite slow. Supply was very difficult for the landing troops on Guam in the first days of the battle. Landing ships could not come closer than the reef, several hundred yards from the beach, and amphibious vehicles were scarce. The 1st Provisional Brigade blocked off the Orote Peninsula on 25 July, and that same night Japanese Lt. General Takashina counterattacked, coordinated with a similar attack against the 3rd Division to the north. The next day,