(7.84) When the day dawned Nicias led forward his army, and the Syracusans and the allies again assailed them on every side, hurling javelins and other missiles at them. The Athenians hurried on to the river Assinarus. They hoped to gain a little relief if they forded the river, for the mass of horsemen and other troops overwhelmed and crushed them; and they were worn out by fatigue and thirst. But no sooner did they reach the water than they lost all order and rushed in; every man was trying to cross first, and, the enemy pressing upon them at the same time, the passage of the river became hopeless. Being compelled to keep close together they fell one upon another, and trampled each other under foot: some at once perished, pierced by their own spears; others got entangled in the baggage and were carried down the stream. The Syracusans stood upon the further bank of the river, which was steep, and hurled missiles from above on the Athenians, who were huddled together in the deep bed of the stream and for the most part were drinking greedily. The Peloponnesians came down the bank and slaughtered them, falling chiefly upon those who were in the river. Whereupon the water at once became foul, but was drunk all the same, although muddy and dyed with blood, and the crowd fought for it.
(7.85) At last, when the dead bodies were lying in heaps upon one another in the water and the army was utterly undone, some perishing in the river, and any who escaped being cut off by the cavalry, Nicias surrendered to Gylippus, in whom he had more confidence than in the Syracusans. He entreated him and the Lacedaemonians to do what they pleased with himself, but not to go on killing the men. So Gylippus gave the word to make prisoners. Thereupon the survivors, not including however a large number whom the soldiers concealed, were brought in alive. As for the three hundred who had broken through the guard in the night, the Syracusans sent in pursuit and seized them. The total of the public prisoners when collected was not great; for many were appropriated by the soldiers, and the whole of Sicily was full of them, they not having capitulated like the troops under Demosthenes. A large number also perished; the slaughter at the river being very great, quite as great as any which took place in the Sicilian war; and not a few had fallen in the frequent attacks which were made upon the Athenians during their march. Still many escaped, some at the time, others ran away after an interval of slavery, and all these found refuge at Catana.