Marines flew, on 13 August, all of the daylight close air support missions in support of the actions on both Bunker in the center and Stromboli in the right of the 1st Marines sector. On 13 August, a total of 94 aircraft were committed over the regimental sector to conduct strikes in support of ground operations. Enemy Hill 104, commanding the 2/1 outpost on 48A (Stromboli), received four attacks. Fighter bombers (F4U propeller-driven Corsairs) carrying napalm, rockets, and 1,000-pound bombs, raided the hill mass at 0535. The other strikes against this key terrain-feature were made by attack and fighter aircraft during the afternoon. Other targets on the regimental right were weapons positions beyond Hill 104 and an enemy outpost one thousand yards west of Stromboli. Most of the air support received by the 1st Marines on the 13th was directed against targets that were participating--or that were capable of taking part--in the battle on Bunker Hill. Against the enemy on the height itself, the Marines directed only three strikes, and these came late in the morning. A majority of the air attacks were dispatched against observation and command posts and the firing positions of both automatic and large caliber weapons. Chinese artillery and mortar fire had inflicted more casualties and punishment on the Marines than the enemy infantry assaults. As a consequence, the main effort of the close air support strikes was directed against these hostile supporting weapons. After dark on the 13th, VMF(N)-513 commanded by Colonel Peter D. Lambrecht,[190] took up the air offensive against the heavy firing positions in the rear of the enemy line. The squadron conducted four attacks with its night fighters. Two of its attacks were made just before sunrise. [190] Two days later, Colonel Lambrecht, flying a F3D twin jet night fighter with his radar operator, Second Lieutenant James M. Brown, disappeared while on a night flight. The last known position of the plane was over the Yellow Sea, 50 air miles west of Pyongyang. At about that point the aircraft faded from the radar screen. Efforts to reestablish communications failed. It was reported that observers at sea sighted a crash and explosion at about this same time. Extensive search failed to uncover any trace of the Marines or their aircraft.