Two union members, Otero, a socialist miner, and Higinio Carrocera, an anarchist steelworker, assumed leadership of the siege. The attackers had cut off the water supply from the outset. The defenders, however, made the city reservoir one of their defended strong points, and with rationing were able to endure the siege. Despite their efforts, however, water could not be used for sanitation. Oviedo was known as a warehouse center for all Asturias, and so the garrison and populace had plenty of food at first. Little fighting occurred until 4 September, when the attackers launched a ferocious aerial and artillery bombardment. An estimated 1,500 bombs were dropped on Oviedo, cutting off the gas, electric, and telephone systems, causing a total blackout of the town. Four days later, supported by an improvised armor-plated steamroller and aerial support, the attackers tried to take the most remote outpost. The defenders reacted by raising several artillery pieces on sandbags to act as anti-aircraft guns. The Nationalist troops were also supported by three
Trubia A-4 tanks from the Infantry Regiment
Milán. The Trubia was basically a Spanish version of the
Renault FT. After a 12-hour battle, the attackers were driven off. The heavy shelling had killed a large number of civilians, but more died due to the lack of water for sanitation. Many people who were sympathetic to the Popular Front joined the forces defending Oviedo because a family member was killed or injured by the attackers' explosives. There was a constant danger of in-town fighting between those loyal to the Republic and the defenders of the siege, but those fears quickly evaporated as the attackers intensified the bombardment and caused more civilian casualties. One advantage to the defenders was that a large portion of the population was politically neutral. A bomb from a Popular Front airstrike killed at least 120 civilians, most of them children and the elderly, on 10 September. The attackers tightened the siege even further as September wore on. Because of the lack of water for sanitation, typhoid broke out and claimed many lives, especially the physically weak, the old, and the very young. As an aside, Oviedo was remarkable during the siege in that the defenders executed none of the political prisoners whom they held in captivity, which was unique at this time on both sides early in the war. ==The final assault begins==