Editing Fort Frank (section)

===World War II===
The fort's design included little protection against air and high-angle artillery attack except camouflage. Also, most of its heavy ammunition was armor-piercing, intended for use against battleships, rather than the high explosive type that would be more useful against enemy troops and artillery.<ref name="Bobart"/>

Fort Frank was heavily engaged in the [[Imperial Japan|Japanese]] [[Philippines campaign (1941–1942)|invasion of the Philippines]]. On 31 January 1942 the fort's mortar battery bombarded mainland positions in the [[Pico de Loro]] Hills that the Japanese were emplacing artillery in. The 75&nbsp;mm guns were also able to engage mainland targets. The Japanese began bombarding [[Fort Drum (Philippines)|Fort Drum]] and Fort Frank on 6 February 1942. Fort Frank was vulnerable in another way: its normal water supply was from a dam's reservoir on the Japanese-held mainland. On 16 February the Japanese discovered this and removed part of the pipeline near the dam. Although the fort also had a [[distillation]] plant to provide fresh water, this consumed fuel that was also needed for the gun batteries' generators that powered the ammunition hoists. The fort's commander ordered the distillation plant started, but also directed a 15-man team to attempt to restore the pipeline on the 19th. They successfully engaged a Japanese patrol but could not get to the pipeline. Eventually another party repaired the pipeline on 9 March.<ref>Morton, pp. 485-486</ref> On 20 March 1942, thirty-four soldiers were killed by Japanese artillery when a round ricocheted into a tunnel at Battery Crofton.<ref name="Bobart"/>

Fort Frank was surrendered, along with all other US forces in the Philippines, on 6 May 1942, after destruction procedures were executed on its guns to prevent their use by the enemy.<ref name="Bobart"/>

During their occupation the Japanese were reportedly able to repair the {{convert|14|in|0|abbr=on}} gun of Battery Crofton and add three {{convert|100|mm|2|abbr=on}} guns. In April 1945, during the [[Philippines Campaign (1944–1945)|American liberation of the Philippines]], Fort Frank was heavily bombarded with {{convert|1000|lb|abbr=on}} bombs and [[napalm]] (among other ordnance) in preparation for recapture. On 16 April 1945 the 1st Battalion, [[151st Infantry Regiment (United States)|151st Infantry Regiment]] and Co. C, 113th Engineer Battalion landed on Fort Frank to find that the Japanese had successfully evacuated the island.<ref name="Bobart"/>