Lewes, East Sussex: The novelist and essayist  Virginia Woolf (born Adeline Virgina Stephen) drowns herself in the River Ouse because she fears another breakdown from which she might not recover.. She was 59. She suffered mental breakdowns in 1895 and 1915.

GERMANY: Daily Keynote from the Riech Press Chief:

Yugoslavia is not kindly disposed toward Germany. When you report events there, your news captions should be shaded so as to make this somewhat clearer but without taking on the form of a threat. Offer no commentary at any time.

YUGOSLAVIA: Belgrade: The Italian Stefani News Agency reported:

This morning at 10:00 A.M., the members of Yugoslavian Premier Simovic's new government were presented to the king. Shortly after that, King Peter Swore his fealty to the constitution in the presence of the Patriarch and high dignitaries of the Serbian Orthodox Church.

King Peter's motorcade from the royal palace to the cathedral, and the return trip to the palace, had the air of a genuine triumphal procession.

British Field Marshal Sir John Dill, Chief of the Imperial General Staff, flies to Belgrade to determine the intentions of the new government headed by Air Force General Dusan Simovic. There is little Dill can offer the Yugoslavs and no agreements of any importance are reached. 

MEDITERRANEAN SEA:The Battle of Cape Matapan. (Cape Matapan is the southern extremity of the Greek mainland, projecting into the Ionian Sea.) This naval battle pits the Italian fleet under Vice Admiral Angelo Iachino, consisting of  the battleship Vittorio Veneto, the heavy cruisers Bolzano, Fiume, Pola  Trento, Trieste and Zara, the light cruiser Giuseppe Garibaldi and 17 destroyers, vs. the Royal Navy fleet under Admiral Sir Andrew Cunningham, consisting of the battleships HMS Barham, Valiant and Warspite, the aircraft carrier HMS Formidable, the light cruisers HMS Ajax, Gloucester and Orion and HMAS Perth, plus 11 RN and two RAN destroyers. The battleships never were in range of each other, but Formidable's aircraft and RAF bombers began attacking the Italian  fleet once in range.

Around 08.30, south of Crete, Adm Pridham-Wippell is in action with an Italian cruiser squadron. Just before noon he finds himself between them and the battleship 'Vittorio Veneto' which has now come up. An attack by Swordfish from HMS Formidable fails to hit the Italian battleship, but enables the RN cruisers to extricate themselves. The Mediterranean Fleet heavy units arrive, but their only chance is to slow down the Italians before they can reach Italy.

The battleship Vittorio Veneto is hit by one torpedo at about 1510 hours, but is still operational. The cruiser Pola is hit and immobilized by a Swordfish bomber and left behind as the Italian squadron turned about to return to base. Admiral Iachino then sent two heavy cruisers and four destroyers back to pick up survivors. The British Battle Fleet continued steaming towards the Italian and picked up the damage cruiser Pola on radar.

At 19.30 a third strike southwest of Cape Matapan stops heavy cruiser 'Pola'. All this time RAF aircraft are attacking but without success.

 Later this evening, two more heavy cruisers - 'Fiume' and 'Zara' with four destroyers are detached to help 'Pola'.

At about 2230 hours, the Battle Fleet is about 1,300 yards (1188 meters) from the Pola and the other six ships who do not suspect that the British are there. Before they reach the Pola, Admiral Cunningham's ships detect them. The three RN battleships open fire with their 15-inch (38,1 centimeter) guns crippling the 'Fiume', 'Zara' and the destroyers 'Alfieri' and 'Carducci'. They are finally sunk by four destroyers led by HMAS Stuart. The battleship Vittorio Veneto escapes and arrives at its base in Italy tomorrow. The Italians lose 2,303 in this battle. 

Cutlasses are used for the last time by the Royal Navy when the Italian heavy cruiser POLA is boarded by the gunners from 'A' Turret, HMS JERVIS, board the battle-damaged Italian ship and rescue the remaining 257 of her bemused crew before sinking the ship. (Bernard de Neumann)
 

Italian torpedo boat 'Chinotto' sinks on a mine laid by HMS Rorqual.

ETHIOPIA: The Italians abandon Diredawa, a town northwest of Harar, and withdraw towards Addis Ababa. 

SOUTH AFRICA: A South African Airways Lockheed Model 18-08 Lodestar, msn 18-2034, registered ZS-AST, crashes into a mountain at Elands Bay. All ten aboard are killed. 

U.S.A.: A team of physicists reports the discovery of a new isotope of uranium which it calls plutonium-239.
[This turns out to be an entirely different element. (Tom Hickcox)]

Republic Pictures releases the first episode of "The Adventures of Captain Marvel." This serial is the first featuring a comic strip or comic book hero.

The Commanding Officer of the aircraft carrier USS Yorktown (CV-5) after five months operational experience with the CXAM radar, reported that aircraft had been tracked at a distance of 100 miles (160 km) and recommended that friendly aircraft be equipped with electronic identification devices and carriers be equipped with separate and complete facilities for tracking and plotting all radar targets.

Hart informed by the Navy Department that he would be retained in command of the Asiatic Fleet beyond his retirement age: Hart turned 64 on June 12, 1941.

Construction of Ford’s Willow Run, Michigan, Plant begins. Before the war, Henry Ford had boasted nonchalantly that Ford could produce 1,000 airplanes per day provided there was no interference from stockholders or labor unions. So when Ford was asked to build subassemblies for the Consolidated B-24 Liberator, it was no surprise that Ford pushed for a deal that would allow Ford to construct the entire bomber. The contract included US$200 million toward the construction of a new production facility. (With inflation, US$200 million in 1941 is equal to US$2.5 trillion in 2003 dollars.) Production got off to a slow start but by the middle of 1944, Willow Run churned out a B-24 every 63 minutes and by the end of the war, Willow Run had produced more than 8,500 B-24s. 
     The Commanding Officer of the aircraft carrier USS Yorktown (CV-5) after five months operational experience with the CXAM radar, reported that aircraft had been tracked at a distance of 100 miles (161 kilometres) and recommended that friendly aircraft be equipped with electronic identification devices and carriers be equipped with separate and complete facilities for tracking and plotting all radar targets.