(CNN) -- A bus trip intended to reward customers of a health-care products company turned deadly when the vehicle plunged off a road in China's northern Shanxi province, killing 13 people, according to state-run Xinhua news agency.
Officials told Xinhua that 41 others were injured in the Friday accident. The bus was traveling on a slippery road amid an afternoon drizzle.
It plunged into a valley while on its way through mountainous terrain on its journey from neighboring Hebei province to the Shanxi capital, Taiyuan.
Jinwanxia, the health-care products company, is based in Taiyuan and had rented the bus for tourism purposes to reward customers.
The accident is under investigation, Xinhua said.