On 1 November 1755, during the reign of King José I, a great earthquake followed by a tsunami and fire destroyed most of Lisbon, including the Ribeira Palace and other buildings by the river. José I's Prime Minister, the Marquis of Pombal, coordinated a massive rebuilding effort led by Portuguese architect Eugénio dos Santos. He designed a large, rectangular square in the shape of a "U", open towards the Tagus. The buildings have galleries on their ground floors, and the arms of the "U" end in two large towers, reminiscent of the monumental tower of the destroyed Ribeira Palace, still vivid in the architectural memory of the city. His plan was realised almost completely, although decorative details were changed and the east tower of the square and the Augusta Street Arch were only finished in the 19th century. This triumphal arch was designed by the Portuguese architect Santos de Carvalho and was completed in 1873. The top section includes statues representing important Portuguese figures such as Vasco da Gama and the Marquis of Pombal.