On 24 August (5 September) the Allies started their sixth and the most severe bombardment of the fortress. Three hundred and seven cannon fired 150,000 rounds, with the Russians suffering 2,000 to 3,000 casualties daily. On 27 August (8 September), thirteen Allied divisions and one Allied brigade (total strength 60,000) began the last assault. The British assault on the Great Redan failed, but the French, under General MacMahon, managed to seize the Malakoff redoubt and the Little Redan, making the Russian defensive position untenable. By the morning of 28 August (9 September), the Russian forces had abandoned the southern side of Sevastopol.