I think it helps to include the 'Clarification', Neveracrossword, because your statement might suggest that Professor Ferguson's model wasn't the basis for the predicted death rate (it was). Here it is -
Clarification: An earlier version of this article said Imperial College researchers predicted that Sweden's approach would leave it with an R of above three, leading to 40,000 coronavirus deaths by May 1. Imperial researchers did not estimate death figures. Instead, Paul Franks, a professor of epidemiology at Lund University, took the Imperial model and made calculations on fatalities. This paragraph has been removed and we apologise for the earlier confusion.