Hi Anthoula,
Your cousin, Sergeant D C Marsh was a crew member of Wellington Mark III,
BJ730, of No 12 Operational Training Unit which took off from Chipping Warden at 2026hrs on 16th September 1942 to attack Essen.
The rest of the crew are listed as,
Pilot Officer F J Adams who was the pilot, Flight Sergeant C W Hall, RCAF, observer, Sergeant N Whitfield ,Wireless Operator/Air gunner and Sergeant G M Caldwell, RCAF Air Gunner. The cause of their loss is not given but theirs was one of 39 aircraft, from a total of 369, which were lost on the raid.
The attack was considered to have been "successful" with 33 large and 80 medium fires. 8 industrial and 6 transport premises were hit. The Krupps industrial complex received 15 high explosive bombs.
Information retrieved from Bomber Command Losses, Vol 3. (Chorley) and
Bomber Command War Diaries, (Middlebrook & Everitt).