( CNN ) -- Eighteen people were killed and 43 seriously injured after the bus they were traveling in plunged into a ravine in a mountainous area south of the Indonesian capital , authorities said . The crash took place Wednesday morning in Puncak , West Java , said Sutopo Purwo Nugroho , a spokesman for the national disaster agency . The passengers on the bus were members of different churches in Jakarta who were returning from a retreat . The cool , mountainous area of Puncak is a popular holiday destination for Jakarta residents . Nugroho said there were indications that the driver lost control of the bus after its brakes stopped working . The bus then rammed into a parked truck and fell into the ravine , he said . The injured are being treated in hospitals in the area . The rugged area is prone to road accidents , and road safety is generally poor in most parts of Indonesia .
The crash took place Wednesday in Puncak , West Java , officials say . The bus was carrying members of parliament from Indonesia . They were returning from a retreat in the mountainous area . There are reports the bus stopped working , an official says .