May 21st, 1944 (SUNDAY)
UNITED KINGDOM: Submarine KNM Utsira (ex-HMS Variance) laid down.
EUROPE: Allied air forces launch Operation Chattanooga, the systematic destruction by bombardment of enemy rail targets.
The USAAF's Eighth Air Force in England flies Mission 360: 150 bombers and 48 fighters hit V-weapon sites in France without loss; 25 of 40 B-17s hit Marquise/Mimoyecques; and 99 of 110 B-24s hit Siracourt. Escort is provided by 48 P-47 s without loss.
617 fighters are dispatched on strafing missions to attack rail stock in Germany; 27 fighters are lost; 91 of 225 locomotives attacked are destroyed; P-47s also dive bomb rail bridges in W Germany; and 1 P-51 pilot claims 25 cows killed; participating are:
- 145 P-38s claim 2-0-0 Luftwaffe aircraft in the air and 6-0-3 on the ground; eight P-38s are lost,.
- 139 P-47s claim 1-0-0 Luftwaffe aircraft in the air; four P-47s are lost.
- 333 P-51 Mustangs claim 17-0-2 Luftwaffe aircraft in the air and 77-0-64 on the ground; 15 P-51s are lost.
The USAAF's Ninth Air Force in England dispatches 50 B-26 Marauders to bomb airfields at Abbeville/Drucat. 600+ P-47s and P-51s attack railroad rolling stock.
MEDITERRANEAN SEA: U-453 sunk in the Ionian Sea NE of Cape Spartivento, in position 38.13N, 16.30E, by depth charges from destroyers HMS Termagant, Tenacious and Liddesdale.
NEW GUINEA: The Airfield at Arare is reopened by US engineers.
TERRITORY OF HAWAII: The accidental explosion of mortar ammunition being loaded in the tank landing ship USS LST-353 at West Loch, Pearl Harbor, destroys this ship and five other LSTs; three tank landing craft (LCTs); 17 tracked landing vehicles (LVTs); and eight 155 mm guns. Two other LSTs are damaged.
U.S.A.:
Minesweepers USS Hazard, Device and Diploma launched.
Destroyers USS Hank and John W Weeks launched.
Destroyer escort USS Vammen launched.
Coast Guard-manned Army vessel FS-176 was commissioned. She was assigned to and operated in the Southwest Pacific area including Tacloban, Hollandia, etc.
ATLANTIC OCEAN: U-995 attacked by an RCAF 4 OTU Sqn Sunderland wounding 5 men.