Rogers' expedition suffered further setbacks. An unidentified disease killed almost a hundred of his expedition members, while leaving the long-term residents nearly untouched. Two of the three navy vessels, having no orders to remain, left for New York. Ships sent to Havana to conciliate the Spanish governor there never arrived, their crew revolting and becoming pirates mid-voyage. Finally, the third naval vessel left in mid-September, its commander promising to return in three weeks—a promise he had no intention of keeping. Work on rebuilding the island's fortifications proceeded slowly, with the locals showing a disinclination to work. On 14 September 1718, Rogers received word that Vane was at Green Turtle Cay near Abaco, about north of Nassau. Some of the pardoned pirates on New Providence took boats to join Vane, and Rogers decided to send two ex-pirate captains, Benjamin Hornigold and John Cockram, with a crew to gather intelligence, and, if possible, to bring Vane to battle. As the weeks passed, and hopes of their return dimmed, Rogers declared martial law and set all inhabitants to work on rebuilding the island's fortifications. Finally, the former pirates returned. They had failed to find an opportunity to kill Vane or bring him to battle, but had captured one ship and a number of pirate captives. Captain Hornigold was then sent to recapture the ships and crews who had gone pirate en route to Havana. He returned with ten prisoners, including captain John Auger, and three corpses. On 9 December 1718, Rogers brought the ten men captured by Hornigold to trial. Nine were convicted, and Rogers had eight hanged three days later, reprieving the ninth on hearing he was of good family. One of the condemned, Thomas Morris, quipped as he climbed the gallows, "We have a good governor, but a harsh one." The executions so cowed the populace that when, shortly after Christmas, several residents plotted to overthrow Rogers and restore the island to piracy, the conspirators attracted little support. Rogers had them flogged, then released as harmless. On 16 March 1719 Rogers learned that Spain and Britain were at war again. He redoubled his efforts to repair the island's fortifications, buying vital supplies on credit in the hope of later being reimbursed by the expedition's investors. The Spanish sent an assault fleet against Nassau in May, but when the fleet's commodore learned that the French (now Britain's ally) had captured Pensacola, he