A bus careered down a Bulgarian mountainside and plowed through pedestrians heading to a religious festival Thursday, killing at least 16 people and injuring at least 20, authorities said, according to AP. Police said the driver apparently lost control of the passenger bus, which was carrying 19 elderly people from a local care home, and could not stop as the vehicle came down a steep mountain road near the city of Yambol, some (160 miles) 260 kilometers southeast of Sofia. The bus hit a crowd of people climbing to the peak on their way to attend a traditional religious feast. Yambol Mayor Georgi Slavov said 16 people were killed and at least 20 were being treated in a nearby hospital. Four of the injured were listed in very serious condition, including one of the bus passengers, an 82-year-old woman.