Tuesday's earthquake comes exactly two years after a magnitude-6.4 quake jolted the island's southern Tainan city, killing more than one hundred people. Most of the deaths were from the collapse of a 16-storey apartment complex, which left many of its residents buried under the rubble. Questions over the building's safety were raised immediately. Five people were later sentenced to five years in jail over the collapse. Taiwan is prone to earthquakes, but 2016's one was the deadliest since 1999.