Hi,
Thank you for your message.
Civil registration began in Ireland in 1864 so you should be able to find Thomas?s death record in these records. They are held in the General Register?s Office in Dublin. Here is a link to their website:
http://www.groireland.ie/research.htm
Indexes to the Civil Registration of Irish deaths are available on Family Search, free of charge. You can search this here:
https://familysearch.org/
You can also search for death records at Roots Ireland ( http://www.rootsireland.ie/ ) and at Ancestry ( http://www.ancestry.co.uk/ie?o_iid=47412&o_lid=47412&o_sch=Web+Property ). However, please be aware that you have to pay to use both of these sites.
I hope that this is helpful.
Kind regards,
Genealogy Support