It tends to be assumed that the the Air Forces Memorial at Runnymede (often simply known as Runnymede) commemorates only missing aircrew, those who flew on operations and never returned, their fate being unknown. However, it does in fact memorialise all RAF personnel who have no known grave.
Amongst the 20,275 names remembered are those of four members of 156 Squadron ground crew, who lost their lives on 9 September 1944 in a catastrophic accidental detonation of bombs at RAF Upwood. No remains of them could be found. They were:
AC2 James Ellis, aged 23
LAC Thomas Graham, aged 25
LAC Herbert Jones, age not known
LAC James Thompson, aged 42
For further details, see the RAF Pathfinders Archive page: Catastrophic Explosion at RAF Upwood
It is thought that the photograph below was taken when Runnymede was opened by the Queen in 1953. Note the sea of flowers and wreaths remembering those who have no grave.