Morrisons in Folkestone was destroyed by a fire that started in the store's cafe on 8 November.
The whale has remained in the river off Gravesend since it was first spotted two months ago.
Police were called on Sunday morning to the Eurotunnel terminal, where the person was declared dead.
BBC correspondents explain the 585 pages
Charts show a big divide across the country
Charlton Athletic left-back Lewis Page signs a new contract until June 2020, with an appearance clause that would trigger an extra year.
Oxford United stretch their unbeaten league run to seven games with victory over Gillingham at the Kassam Stadium.
East Kent Mercury
Gravesend Reporter 24
About these results
As BBC Radio 5 live
An exclusive mix of Theroux's favourite songs
Sign up for our newsletter