2 of his children probably die young:
Deaths March quarter 1925
Warren Duncan 0 Sheffield 9c 650
Deaths June quarter 1930
Joan Duncan 0 Sheffield 9c 560
And this one not showing on free bmd:
Irene Duncan June quarter 1923 Age at Death: 0
Sheffield 9c 534
The only surviving daughter has a very common first name, so you would need the birth certificate to trace her death - there is a possible one for her if she did not marry, but many marriages available around the region.
