The Americans began their siege of the city. U.S. artillery sited on the heights pounded the city, while U.S. forces supported by Cuban rebels choked off all water and food supplies to the city. On July 3, a relief column was able to fight its way through Garcia's rebels and into the city bringing Toral's force to a total of 13,500. On July 4, a cease fire was enacted to evacuate roughly 20,000 citizens from the city. Also, on July 4, four .30 Army Gatlings from Lt. John Parker's Gatling Gun Detachment were moved to Fort Canosa in support of the siege, as was a dynamite gun and sixteen field guns. Over the next thirteen days, the Gatlings were used to fire 6,000 to 7,000 rounds into the city of Santiago, causing many casualties.