At five o'clock the fire of the northern battery suddenly ceased, and the peal of a single gun immediately announced the moment of action. The report had scarcely died away, when it was echoed by a cheer from the British grenadiers, as, springing from their ambush, they rushed headlong towards the breach. A French officer of Cambon's regiment first mounted it, waved his sword, and pointed onward, when the Irish soldiers rose from their cover, levelled their muskets on the advancing foe, and in a moment the gallant Frenchman and many of his immediate followers were numbered with the dead. Still they pressed on, and hundreds of them thronged the breach, when a second volley, more deadly than the first, swept through their ranks, and the defenders stepped forward and stood to confront the whole force of the assailants. The conflict now became desperate, but the result could not be long doubtful; overwhelmed by numbers, they were borne through the breach, and the enemy gaining the open space inside the wall, commenced filing to the right and left in pursuance of their purpose. The way to the right was narrow and tortuous, and, though pressed on by the weight of 2,250 men, their way was disputed foot by foot, and dearly purchased in that direction. But that to the left being less obstructed, the result was terribly ruinous to the defenders. At the end of an hour one-half of them lay dying and trampled among the _débris_, and still the rest stood and fought as resolutely as ever. At length the gate was gained, the assailants thronged by thousands into the market-place, and the strife was transferred to the street leading down from it to the river. Another hour passed on, and the defenders were borne back towards the bridge; its destruction was not yet completed; and to win it on the one side and maintain it on the other, became the work of life and death. The assailants rushed on in their fury, but were steadily resisted, and even for awhile repelled, their overwhelming numbers defeating the very object of their assault. At length the arch was sprung, the word was given to retire; the defenders rushed along the bridge; some of them succeeded in crossing it, but their assailants pressing closely on them, many were borne over the battlements, to rise no more. Further persistence was now in vain; the work was done; the arch had given way, and sunk beneath the waters of the river; and the enemy retired under an effective fire opened on them from the opposite side; the bridge was rendered impassable.