Colombia on Wednesday declared three days of mourning for victims of an earthquake that killed more than 200 people and demolished scores of buildings in the west of the country. At 7.4 magnitude, Monday's quake was the strongest to hit Colombia this century. The government said flags would be lowered to half-staff on official buildings, as well as at Colombian embassies abroad, "in honour of all the dead", who are now numbered at 216. In the cities of Pereira and Cali, emergency crews worked through the night with cranes, dogs and heavy machinery in the hunt for survivors, while volunteers formed human chains to clear debris by hand. There was joy when rescuers pulled out 32-year-old Daniela Largo alive after 35 hours trapped in the rubble of a Pereira hotel. Read moreWoman rescued from rubble two days after Colombia's deadly quake "We were losing hope and then we received a call," her mother Sandra Milena Perez told AFP. Perez said a local resident heard cries for help beneath the rubble and joined neighbours in removing debris before professional rescuers arrived. "I thank him with all my heart because thanks to him today we are happy... a son is waiting for her at home," she said. The first two days after an earthquake are crucial for finding survivors under rubble, with some experts saying that after a 72-hour window, hopes quickly fade. From the air, neighbourhoods in Cali appeared flattened, with piles of grey rubble replacing entire blocks of homes and apartment buildings. Nearby, cars lay crushed beneath fallen walls and concrete slabs.