The 24-year-old fell 26 feet off a beach promenade on Saturday night in the French city.
The man died just hours before Northern Ireland were due to get their tournament underway against Poland.
It is believed that his death was accidental, but his name has not yet been released.
A 24-year-old Northern Ireland football fan has died in hospital in Nice, France, after falling 26ft off beach promenade on Saturday night.
— Peter Allen (@peterallenparis) June 13, 2016
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