There are burial slips from Warwick Cemetery on Ancestry which give dates and address at death for Frederick and some of his wives, but not cause of death unfortunately. I can see Frederick George Hirons d. 1917, Hannah d. 1899, Flora Jane d. 1904 and Emma Rose d. 1902 all buried there.
Also at Warwick Cemetery:
Ada Daisy Hirons, child of Frederick George Hirons of 27 Market St, died 25 Jan 1902 age 21 days (born 4 Jan 1902).
Rose Emma [sic] Hirons died 9th January 1902, same address, wife of Frederick George Hirons
So that death looks like post-childbirth complications.
Lloyd George Hirons is there as well, d. 6th Nov 1919 age 9 "child of Sarah Ellen Hirons, 22 Market St"
Have a look if you can, there may be other names, addresses and clues that will help.

Barbara