bombing operations. Bomber wings under Sperrle's command struck at Swansea. 101 high explosive and several hundred of other types of bombs were dropped disrupting the Great Western Line. In March the intensy of bmbing operations increased, Luftflotte 3 flew 2,650 operations. Attacks against Cardiff in March 1941 caused some of populace to evacuate the city, a phenomenon known as "trekking". Such incidents caused only temporary drops in morale. Other bombing operations were carried out against Liverpool by 316 aircraft, Glasgow by 236, Bristol by 162 bombers, London by 479 aircraft Portsmouth by 238 and Plymouth over two nights by 125 and 168 bombers. In April 1941 the Midlands bore the brunt of German bombing raids with only three nights respite, 75 percent of them carried out by Sperrle's air fleet. Birmingham was bombed on consecutive nights by 237 and 206 aircraft. Coventry was also subjected to a 237-bomber attack. British ports were also targeted as part of 16 major and five heavy attacks. Plymouth, Glasgow and Belfast were bombed in mid-April and morale was severely effected. Plymouth was bombed on five of the eight nights from 21 to 30 April by 120, 125, 109, 124 and 162 aircraft. The Port of London was bombed by 685 aircraft on 16 April and by 712 on 20 April. April was the most intensive month of the Blitz for Luftflotte 3 in 1941—approximately 3,750 bombing operations in comparison to 1,500 by Kesselring's air fleet. In May 1941, the final full-month of the German night offensive, Luftwaffe forces operating against western cities in Britain bombed Dublin, ostensibly in error. Luftflotte 3 regularly operated over North West England, against Liverpool and Manchester. On 31 May 1941, Sperrle's air fleet made a huge navigational error, and bombed the Irish capital, situated some 200 miles from their targets in Liverpool. During May units belonging to the air fleet were involved in the Hull and Nottingham Blitz. A last effort was made against London on 10 May. 571 bombing missions were flown against the embattled capital that night. During the month, Sperrle's men carried out the burden of night operations, flying 2,500 sorties in comparison to 1,300 from Luftflotte 2. Approximately 40,000 British civilians had been killed, another 46,000 injured, and more than a million houses damaged during the Blitz. The German air fleets lost 600 German aircraft on night operations. The Coventry raid, which for a short