This was a British and US air attack on shipping in the harbour of Venice on the north-east coast of Italy (21 March 1945).
In January photo-reconnaissance sorties had revealed that Venice was becoming a centre for the delivery of supplies to General Traugott Herrís 10th Army in the north-eastern part of Italy. Careful preliminary work was effected during February, when mines were laid in two fields outside the main harbour and others in the entrance. On 18 March air reconnaissance confirmed that there was now a sufficient concentration of shipping and barges in Veniceís harbour to make this a worthwhile target, and authority was given to attack with the proviso that no historic and cultural building would be placed at risk.
As a result only selected air crews were to be used for the operation to ensure that only precisely defined areas were attacked. Air Vice Marshal R. M. Fosterís Desert Air Force (with No. 239 Wing of the RAF and Colonel Gladwyn E. Pinkstonís 79th Fighter Group of Major General John K. Cannonís US 12th AAF) was made responsible for the operation.
The right weather conditions were available for 21 March, but an early morning mist then delayed matters until a time early in the afternoon. Then 16 North American Mustang fighters of No. 260 Squadron, RAF, and 20 Republic P-47 Thunderbolt fighters of the 79th Fighter Group attacked soon after 15.30 with bombs, rockets and machine guns to suppress 45 Flak positions, some of which were well protected and difficult to neutralise. All the Flak positions appeared to have been silenced when the main force of 24 Curtiss Kittyhawk and 40 Mustang fighter-bombers began to attack the dock area. In 20 minutes 800 20-lb (9.1-kg) fragmentation bombs, 93 1,000-lb (454-kg) HE bombs, and 31 260-lb (118-kg) semi-armour piercing bombs were dropped, and 114 air-to-surface rocket projectiles were fired. One dock-side explosion was so great that it was felt by reconnaissance aircraft at 20,000 ft (6095 m), and smoke obscured the scene. The 3,682-ton Otto Leonhardt was severely damaged and seen submerged two days later. Two German-crewed Italian torpedo boats, one small freighter, and two lighters were sunk, and dock-side installations, rolling stock and railway track were severely damaged. Only one bomb fell outside the defined area and only one aeroplane was lost, its pilot being saved.
The operation was the last attack on an Italian port before the end of the war.