of World War I, San Sebastian became a destination for renowned international figures of culture and politics, including Mata Hari, Leon Trotsky, Maurice Ravel, and Romanones. San Sebastian was one of earliest towns hit by the 1918 Influenza epidemic, dealing with a first wave outbreak in February of that year. Officials feared for the city's reputation and attempted to keep the disease's spread quiet, to no avail, and the outbreak soon spread throughout Spain. Various rationalist architectural works, typically white or light-coloured, were built in the 1920s and 1930s, such as La Equitativa, Nautico, and Easo. In 1924–1926, canalisation work was carried out on the Urumea river at the southern edge of the city. However, after the city's Belle Epoque in the European wartime, repression under Miguel Primo de Rivera's dictatorship was not favourable for the city. In 1924, gambling was prohibited by the authoritarian regime, causing existential problems for the Grand Casino and the Kursaal (1921). In 1930, Spanish republican forces signed up to the Pact of San Sebastián, leading to the Second Spanish Republic. Unrest and repression did not stop with the new political regime, and large-scale industrial action was called several times by the growing anarchist, communist and socialist unions. The 1936 military coup was initially defeated by the resistance, led by the Basque Nationalists, anarchists and communists, but later that same year the province fell to Spanish Nationalist forces during the Northern Campaign. The occupation proved disastrous for the city's residents. Between 1936 and 1943, 485 people were executed as a result of show trials by the Spanish Nationalists (Requetés and Falangists). It has been estimated that extrajudicial executions (paseos) by the occupying military forces accounted for over 600 murders in the area during the first months of occupation. Many children were evacuated to temporary safety in Bilbao, with the city's population falling by an estimated 40,000 to 50,000 inhabitants. In the aftermath of war, the city was stricken by poverty, famine and repression, coupled with a thriving smuggling trade. Many republican detainees were held at the beach-side Ondarreta Prison in grim and humid conditions, until the building was demolished in 1948. However, industrial development paved the way for urban expansion in the Egia and Amara Berri districts, on the marshes and riverbed of the Urumea, at the end of the 1940s and beginning of the 1950s. In 1943, the first Basque language schools were established