prospecting and construction and being delayed since the 1980s after the 1985 Algarrobo earthquake and the changing demographics of the city during the '80s and '90s. Its rolling stock material is identical to the Line 6 and were built simultaneously, so they're considered "twin lines". 2019 protests During the month of October 2019, the Santiago metro network was affected by social protests due to the increase in the fare of the entire Metropolitan Mobility Network. Initially, secondary students staged massive acts of evasion between 6 and 11 October. The protests quickly escalated to several metro stations, resulting in train service being repeatedly interrupted. On Friday the 18th, the situation escalated and the entire network had to be closed due to attacks on stations and workers. At night, after the declaration of a state of emergency by President Sebastián Piñera, several stations of the Metro were destroyed and burned, some of which were attacked again the next day, even though a curfew had been established. Meanwhile, the Instituto Nacional de Derechos Humanos investigated accusations that the Baquedano station was used as a detention and torture center by police and military. On the morning of the same day, the site was reviewed by staff from the INDH, PDI and guarantee judges. The judges found no evidence of torture or illegal detentions at the site, but an investigation was launched to rule out any irregular situation. The Metro network had been partially reactivated as of Monday, October 21; however, due to the damage of some stations, the network will only be available in its entirety within a period of up to 7 months. Damage costs are estimated at more than $300 million. Metro de Santiago indicated that it does not have insurance contracted for the infrastructure of the stations and trains. Lines 3 and 6, meanwhile, opened on 23 October, Lines 2 and 5 on the 25th, Line 4 on the 28th, and line 4A on November 25, in all cases partially and on a shortened schedule. On October 23, it was reported that 79 stations had been damaged in all, with lines 4, 4A, and 5 having the highest number of stations destroyed or vandalized. There were also damage to 6 trains, 5 on line 4 and one on line 1 - the latter set on fire at the San Pablo station. Upon the reopening of the last two stations (Trinidad and