Authorities also confirmed four people were killed in Choco and two more in the city of Manizales in the Caldas region. Residents and search teams picked through the rubble of collapsed buildings amid concerns by authorities of aftershocks. Most powerful quake in the last decade, authorities sayJorge Moncayo, a 64-year-old taxi driver in Cali, said he saw plumes of dust shoot up across the city as buildings collapsed. Powerful quakes are rare in Colombia, where smaller quakes are commonSmall earthquakes, known as “temblores,” are common in central and western Colombia, but those above 6.0 magnitude are rare. In 1999, a 6.2 magnitude quake near the city of Armenia killed more than 1,100 people.