In 1644, with the death of Pope Urban with whom Bernini had been so intimately connected and the ascent to power of the fierce Barberini-enemy Pope Innocent X Pamphilj, Bernini's career suffered a major, unprecedented eclipse, which was to last four years. This had not only to do with Innocent's anti-Barberini politics but also to Bernini's role in the disastrous project of the new bell towers for St. Peter's basilica, designed and supervised entirely by Bernini. The infamous bell tower affair was to be the biggest failure of his career, both professionally and financially. In 1636, eager to finally finish the exterior of St. Peter's, Pope Urban had ordered Bernini to design and build the two, long-intended bell towers for its facade: the foundations of the two towers had already been designed and constructed (namely, the last bays at either extremity of the facade) by Carlo Maderno (architect of the nave and the facade) decades earlier. Once the first tower was finished in 1641, cracks began to appear in the facade but, curiously enough, work nonetheless continued on the second tower and the first storey was completed. Despite the presence of the cracks, work only stopped in July 1642 once the papal treasury had been exhausted by the disastrous War of Castro. Knowing that Bernini could no longer depend on the protection of a favorable pope, his enemies (especially Francesco Borromini) raised a great alarm over the cracks, predicting a disaster for the whole basilica and placing the blame entirely on Bernini. The subsequent investigations, in fact, revealed the cause of the cracks as Maderno's defective foundations and not Bernini's elaborate design, an exoneration later confirmed by the meticulous investigation conducted in 1680 under Pope Innocent XI.