Four more of these ferocious attacks, combined with a terrific cannonade from the Constitution, and the assistance from the brigs and schooners, lost the Tripolitans many of their most serviceable craft, and made those that were left very shy of coming outside the reefs to meet the "Americanos." The great guns on the Constitution had knocked to pieces many of the more exposed land batteries, and brought down the Bashaw's tone immeasurably. He was then anxious to negotiate, but Commodore Preble would listen to nothing but the unconditional surrender of Bainbridge and his men. The loss of the Americans was small in numbers but great in value during the bombardment, and was confined chiefly to the gunboats. In the second attack, on the 7th of August, one of the American gunboats blew up, killing her brave commander, Lieutenant Caldwell, and several others. When the smoke cleared away after the awful explosion, it was seen that the forward part of the vessel still floated. On it was the long twenty-six-pounder, which was her chief weapon, and which the gun's crew, directed by Midshipman Spence, had just loaded. With as much coolness as if there had been a whole vessel instead of a half one beneath them, the gun was fired, the eleven men on the wreck gave three cheers, led by the midshipman, and then sprang into the water. All were picked up, and fought during the rest of the action. There was another attack on the 28th of August, and again on the 3d of September. In this last the Constitution bore the brunt of the Tripolitan fire, and did fearful execution with her heavy guns. And on the 4th of September occurred the terrible tragedy of the blowing up of the ketch Intrepid.[11]