At 4 AM, U-161 approaches the harbour at Puerto Limón, Costa Rica, and sinks Panamanian SS San Pablo at the pier, unloading a cargo from New Orleans (most of the crew are ashore but 1 crewman and 23 stevedores working in the holds are killed). 50 miles North of Trinidad, U-126 badly damages US tanker SS Gulfbelle (2 killed). Although most of the crew abandon ship, SS Gulfbelle does not sinks and is towed by British destroyer HMS Warwick to Port of Spain, Trinidad (then towed to Mobile, Alabama, for repairs, arriving on September 8, and returned to service in July 1943).
At 12.30 PM 186 miles East of Chatham, Cape Cod, U-215 sinks American SS Alexander Macomb on her maiden voyage carrying 9000 tons of military equipment, tanks, planes and explosives to USSR (4 crew and 6 gunners killed, 37 crew and 20 gunners rescued by British anti-submarine trawler HMS Le Tiger and Canadian corvette HCMS Regina). HMS Le Tiger then counterattacks and sinks U-215 with depth charges (all 48 hands lost).
7 B-24 Liberator bombers (US 11th Air Force) attack Japanese seaplane anchorage at Agattu Island, Aleutians, damaging oiler Fujisan. A near-miss kills several crewmen aboard seaplane carrier Kimikawa Maru.
First Battle of El Alamein. Overnight, British reinforce Ruweisat Ridge (the force is now known as “Walgroup", still under Brigadier Robert Waller). Rommel attacks Ruweisat Ridge again with 15th and 21st Panzer Divisions, adding Italian XX Motorised Corps, but they are held by Waller’s artillery and RAF bombing. New Zealand 2nd Division advances from the Qattara “box”, near the Qattara Depression, to break up the Axis attack and routs Italian Ariete Division which loses 531 troops (350 taken prisoners), 36 artillery pieces, 6 tanks and 55 trucks. By the end of the day, Afrika Korps has only 26 operational tanks while Ariete Division has 5.
Case Blue. German 4th Panzer Army crosses the Don River near Voronezh but meets stiffening resistance from Soviet forces. Hitler flies to Poltava, Ukraine, to discuss the slow progress of the operation with General von Bock, commander of Army Group South. They argue over the next steps, with Hitler wanting to stick to the plan and advance South to the oilfields while von Bock worries about the Soviet forces gathering on his flank and insists on securing Voronezh.
Kriegsmarine pocket battleships Lutzow and Admiral Scheer and 6 destroyers depart Narvik to meet battleship Tirpitz, cruiser Admiral Hipper and their escorts, prior to foraying against convoy PQ 17. Lutzow and 3 destroyers run aground. 9 British and 7 Soviet submarines deploy to intercept the German battlegroup. Soviet submarines D-3 and M-176 are lost in German minefields.