Able Seaman Desmond O'Connor died during operations at Elba [1][2].
Mentioned in Despatches (posthumous) for distinguished service in operations carried out in the face of determined opposition from the enemy which led to the capture of the island of Elba [3]. At the time of his death RN Commandos were involved in the operation to liberate the enemy occupied island of Elba, codenamed Operation Brassard.

Sources
[1] CWGC
[2] Registers of Deaths of Naval Ratings / National Archives file ADM104/135.
[3] London Gazette 36783, page 5088.

Notes
The CWGC list his unit as HMS Copra. This was a shore base in the UK responsible for the Pay and Records of RN personnel attached to Combined Operations. He was not serving there at the time of his death. Commando service needs to be verified through service record when available. His MiD was not shown on the CWGC record. They have been informed and have now amended it accordingly.