Thankyou Sue,
Yes I did find that about daughter Catherine....quite sad isn't it? Son Thomas also died in the Asylum so it sounds like they endured a bit of hardship. The informant on Catherine's death certificate was Andrew Chung, my great grandfather. He was married to Elizabeth Lee Fung, daughter of Ellen Fitzgerald (and husband Lee Fung). I have a feeling that William may have been a bit of a wanderer. On all the electoral rolls for Catherine, it is her name alone so either William was deceased before her, or he ended up somewhere else.
There are three deaths on Vic BDMs that are a possibility, one of which I ordered but wasn't him (I don't think so anyway!):
William Fitzgerald
Birth Year: abt 1819
Age: 58
Death Place:Victoria
Father's Name:William
Mother's Name:Ann Basley
Registration Year:1877
Registration Place:Victoria
Registration Number:1865
Wm Fitzgerald
Death Registration Year:1890
Death Registration Place:Victoria, Australia
Reference Number:15280
William Fitzgerald
Occupation: Dairyman
Date of Death: 24 April 1908
Age: 86
Place of Death: Melbourne Benevolent Asylum
Father: John Fitzgerald
Mother: Ellen Maloney
Born: Galway, Ireland
Years in Victoria: 54
Spouse: Widower, no other particulars
Children: no issue
This is the record I ordered. I did find him in either the electoral roll or Sands & McDougall directories (can't remember off hand!)and his wife wasn't Catherine so it is a possiblity he remarried but to say he had no children didn't quite fit.