Hit by flak. Ten miles SW of Antwerp, at Bazel on the west bank of the Schelde river, they had tried to crash land but ultimately ditched. Both killed, their bodies were washed ashore and subsequently laid to rest in Antwerp's Schoonselhof cemetery.
Details from Stuart Scott's "Mosquito thunder"
Not sure if this detail fits with recovery of the wreckage mentioned i.e. this aircraft came down in water.