It seems he's pulling that number out of thin air: perhaps he's conflating it with the general Warsaw uprising. The German figures are about 20 killed, and abo

It seems he's pulling that number out of thin air: perhaps he's conflating it with the general Warsaw uprising. The German figures are about 20 killed, and about 100 injured. Marek Edelman (a leader of the uprising) had an optimistic estimate of about 300 casualties. So the likely figure is likely somewhere between.