Four months later, Estrada's death from a heart attack precipitated a brief civil war that climaxed the rivalry between Alfaro and Plaza. Alfaro returned from his exile in Panama to lead the Guayaquil garrison in its challenge to the Quito-based interim government, which was under the military authority of General Plaza. The rebellion was quickly defeated, however; Alfaro was captured and transported to Quito via the same railroad that he had done so much to complete. Once in the capital, Alfaro was publicly and unceremoniously murdered, along with several of his comrades, by a government-instigated mob. Uprisings by his supporters (see Concha Revolution) were crushed. Shortly thereafter, Plaza was inaugurated into his second presidential term in office. It was the first of four consecutive constitutional changes of government: following Plaza (1912–16) came Alfredo Baquerizo Moreno (1916–20), then José Luis Tamayo (1920–24), and Gonzalo Córdova (1924–25). Real power during this second half of the period of Liberal rule was held, not by the government, but by a plutocracy of coastal agricultural and banking interests, popularly known as la argolla (the ring), whose linchpin was the Commercial and Agricultural Bank of Guayaquil led by Francisco Urbina Jado. This bank gained influence by loaning vast quantities of money to the free-spending government as well as to private individuals. According to Ecuadorian historian Oscar Efren Reyes, the bank was influential "to the point that candidates for president and his ministers, senators, and deputies had to have the prior approval of the bank". Many of the private loans were to members of the Association of Agriculturists of Ecuador, an organization that also received government funds intended to promote an international cartel of cacao growers, but which instead were used to line members' pockets. All parties involved in la argolla, from the government officials to the bankers and the growers, were professed militants of the Liberal cause. It was not only the political fortunes of the party that fell victim to their financial activities, however, but also the national economy, which experienced runaway inflation as a result of the printing of money by the private banks. The severe economic problems during the final years of Liberal rule were also partially caused by factors beyond the control of the politicians. A fungal disease that ravaged Ecuador's cacao trees and the growth of competition from British colonies in Africa abruptly ended conditions that had favored Ecuador's exportation of cacao for over a century.