http://www.onwar.com/chrono/1942/may42/f04may42.htm
Japanese bombarding Corregidor
Monday, May 4, 1942 www.onwar.com
In the Philippines... Fighting lessens on Mindanao. Japanese bombardment of the American forces on Corregidor is very intense.
In the Coral Sea... Aircraft from the USS Yorktown positioned 100 miles south of Guadalcanal, attack Japanese forces off Tulagi. The Yorktown then returns south to join the American Task Force 17 which is assembling to engage the Japanese. American actions are dictated by their code breaking which has revealed many of the Japanese plans to them.
In Burma... Chinese units are forced to withdraw from Wanting on the all important Burma Road and at Bhamo on the Irrawaddy. At Akyab, the British evacuate before Japanese advances.
http://corregidor.org/btty_histories/control/open.htm
The artillery had begun its preparatory fire on 1 May and by the evening of the 5th had laid waste the entire north shore of Corregidor. That night, after the first troops had embarked at Lamao, the artillery concentrated first on the remaining mobile guns and searchlights on the island and then on the stretch of beach between Infantry and Cavalry points. Just before the landing, the artillery had shifted its fire westward, to Malinta Hill. To assist in artillery fire that night and next day, General Kitajima had placed a liaison group of sixty men in the assault boats. They would go ashore with the first waves and establish artillery observation posts on Malinta Hill as soon as it was taken.
By the time the artillery and air forces had opened the final phase of the bombardment, the 4th Division had won its fight against malaria and was ready to move into the assembly area. On 4 May, X minus 1, Colonel Sato had assembled his left wing units in the Lamao River valley, near Cabcaben, and the next day marched them to Lamao where, at dusk, they began to embark for Corregidor. The run to the island was made in darkness, the troops expecting to land about 2300, an hour before moon-rise. Earlier that day, after Sato moved out, General Taniguchi’s right wing assembled near Cabcaben in preparation for their assault the next night, 6 May.
http://usswashington.com/worldwar2plus55/dl03ma42.htm
May 4th, 1942...HMNZS Achilles and HMNZS Leander arrive in Vila, and stay there for two weeks, assisting to unload ammunition from storeships to barges, and providing AA protection while American Seabees build roads, barracks, supply dumps, and a workable airstrip.
At 6:30 a.m., 12 Devastator torpedo bombers and 28 Dauntless dive bombers from the carrier USS Yorktown attack the massed Japanese ships at Tulagi. The raid catches the Japanese and coastwatcher Martin Clemens by surprise. The American planes swoop down, and overestimate what they see, identifying a minelayer as a light cruiser, and minesweepers as transports. They hammer the targets and go home by 9:30, having sunk the destroyer Kikuzuki and three minesweepers. A second strike punches out two seaplanes and damages a patrol craft, while a third attack sinks four landing barges. The Americans lose only three planes. Despite the elated mood on Yorktown, Japanese losses are minor. The Battle of the Coral Sea has begun.
In Hashirajima Bay, Japanese senior officers wargame the attack on Midway, using a complex game developed by their officers. Battle results are determined by dice roll according to combat results tables, to introduce random events. In the paper battle, American carrier planes catch the Japanese carriers Akagi and Kaga and sink them. Vice Adm. Matome Ugaki overrules umpire Masatake Okumiya to refloat Akagi. In the follow-up game, Kaga is also re-floated...and in both battles, the Japanese win. Success thus assured, the mimeograph machines start to roll, and the Navy is directed to carry out “General Order No. 18,” which will attack targets “AO” and “AF.” The air is soon thick with radio transmissions, coded in JN-25, the top-level code.
These messages all land on the desk of Cdr. Joseph Rochefort, a Japanese-speaking intelligence officer at Pearl Harbor, who heads FRUPAC, the Pacific Fleet’s team of codebreakers, who, after a great deal of sweat and mathematics, can unreel JN-25. Many of the messages refer to a target named “AF.” Nobody can figure out what it is, until an officer looks down a Japanese map and observes that Midway stands at the cross of grids “A” and “F,” and that an enemy snooper plane reported being near “AF” when on a flight near Midway. CINCPAC, Adm. Chester Nimitz, believes this theory. Washington, however, does not. Adm. Ernest King fears a Japanese assault on Hawaii or a raid on the West Coast. The Army worries about an attack on the Panama Canal. Washington demands proof of Rochefort’s theory.
On Corregidor, the Americans, down to one week’s water, are ready for the worst. AA guns are out. Telephone lines are out. Rations are down to a little canned salmon and rice. Showers are out. The last Navy gunboat, Mindanao, has been sunk. The last two PBYs from Australia have flown in to evacuate 50 passengers, including radio intercept specialists and nurses. Wainwright expects the invasion next evening, during the full moon.
Japanese troops invade Mindanao at Cagayan and press south along the Sayre Highway, a dirt track.