Bombing of Darmstadt in World War II
Darmstadt was bombed a number of times during World War II. The most devastating air raid on Darmstadt occurred on the night of 11/12 September 1944 when No. 5 Group the Royal Air Force (RAF) bombed the city.
Darmstadt had a few industrial targets of note, a Merck chemical factory being one of them. By comparison with other German cities, preparations for bombing raids were less effective and flak defences had been depleted to provide defence for other cities.
Minor raids 
On the night of 23/24 September 1943 Darmstadt was bombed by 21 Avro Lancasters and 8 De Havilland Mosquitos of No. 8 Group RAF. Although it was a diversionary raid to draw night fighters away from for the main raid on Mannheim with 628 aircraft, the small force of bombers caused extensive damage in the university town that had little industry and which had not been seriously bombed before.
An attack on the night of 25/26 August 1944 by No. 5 Group RAF was a failure. The Master Bomber had to return to base and his deputies were shot down en route. The pathfinder "Illuminating Force" flares were dropped too far to the west. As a result, most of the Main Force did not bomb at all, with a number diverting to bomb Russelsheim instead. 95 buildings were hit in Darmstadt and 8 people were killed by the scattered bombs which did hit the town.
Main raid 
The main raid on Darmstadt was by No. 5 Group RAF on the night of the 11/12 September 1944, when 226 Lancasters and 14 Mosquitos, was directed to the medieval city centre as houses there were mainly built of wood. The raid was to incorporate a new technique where, instead of bombers flying along a single path across the target, the bombers would bomb along a fan of paths over the city. The intention was to deliberately spread the bombload.
The attack started a fierce fire in the centre and in the districts immediately to the south and east. The destruction of dwellings in this area was almost complete. The raid killed an estimated 12,300 inhabitants and rendered 66,000 homeless out of a total of 110,000 inhabitants. The RAF lost 12 Lancasters, 5.3 per cent of the Lancaster force. Darmstadt became one of the German cities with the highest rate of killed civilian population.
Royal Air Force Bomber Command 60th Anniversary Campaign Diary for September 1944 states:
- The Darmstadt raid, with its extensive fire destruction and its heavy casualties, was held by the Germans to be an extreme example of RAF 'terror bombing' and is still a sensitive subject because of the absence of any major industries in the city. Bomber Command defended the raid by pointing out the railway communications passing through Darmstadt; the directive for the offensive against German communications had not yet been issued to Bomber Command, although advance notice of the directive may have been received. Darmstadt was simply one of Germany's medium-sized cities of lesser importance which succumbed to Bomber Command's improving area-attack techniques in the last months of the war when many of the larger cities were no longer worth bombing.
References & notes 
- Royal Air Force Bomber Command: Campaign Diary September 1943
- Royal Air Force Bomber Command: Campaign Diary April 1944
- Royal Air Force Bomber Command: Campaign Diary August 1944
- Hastings p394
- Royal Air Force Bomber Command: Campaign Diary February 1945
- Royal Air Force Bomber Command: Campaign Diary September 1944
- Hastings, Max Bomber Command