Relying solely on private donations, the Sagrada Família's construction progressed slowly and was interrupted by the Spanish Civil War. In July 1936, revolutionaries set fire to the crypt and broke their way into the workshop, partially destroying Gaudí's original plans, drawings and plaster models, which led to 16 years of work to piece together the fragments of the master model. Construction resumed to intermittent progress in the 1950s. Advancements in technologies such as computer aided design and computerised numerical control (CNC) have since enabled faster progress and construction passed the midpoint in 2010. However, some of the project's greatest challenges remain, including the construction of ten more spires, each symbolising an important Biblical figure in the New Testament. It is anticipated that the building can be completed by 2026, the centenary of Gaudí's death.