There is only 1 Sunderland Birth that fits, but I cannot tie that to the man that died in Derry in 1921. All we have is that the man who died was from Sunderland, aged 19, with a father Frederick.
1903 Oct 6. Born Sunderland
1907 Went to school , father Fred of 24 Horatio St, Roker, Sunderland
1918 Seaman's Card
Enlisted in KOYLI
The Irish GRO entries point to an Edward b1902 as more likely. There is a James B Wright in Sunderland, b1902 but Ancestry trees appear to show it is not him.
Killed by another soldier in Londonderry , Private W Keen, while both on sentry duty
Londonderry Sentinel 7 April 1921 shows that a Private J Wright was buried at the Londonderry City Cemetery 5 April 1921 having been died at the Infirmary on 2 April 1921 after being shot at Shipquay Street.
Northern Whig 4 April 1921 inquest shows that Private Wright was shot at about 0330hours 2 April 1921
The Death Cert and Soldiers Effects shows that his name is not J Wright, but Edward Wright who died at the infirmary having been shot 2 April 1921. DC states soldier aged 19. Cemetery records show that Edward Wright of England aged 19 who died 1 April 1921 is buried in Section G. And CWGC docs show that section G was used as the burial plot for the garrison.