premise: A whale that became stranded in the River Thames has died after a massive rescue attempt to save its life. The 18ft (5m) northern bottle-nosed whale was first spotted in the river on Friday and rescuers began an attempt to save it on Saturday morning. But the whale died at about 1900 GMT on Saturday as rescuers transported it on a barge towards deeper water in the Thames Estuary.
hypothesis: A whale died in the River Thames.