Four people were killed and fifteen were injured after an eighteen-wheeled truck lost control on a hilly stretch of highway in a Thai National Park on Saturday evening.

The accident occurred when the driver of the 18-wheel trailer truck heading downhill lost control and its trailer swept away five vehicles that were heading uphill from the opposite direction,

Reports say the driver was driving downhill when the accident occurred. His brakes failed halfway down the hill causing him to lose all control and side-swipe five vehicles that were heading uphill in the opposite direction.

The crash happened around 6pm. It was raining heavily at the time. The vehicles swept off the highway were two passenger cars, two passenger vans and a chopper motorcycle.

Three people were killed instantly and one succumbed to injuries on the way to the hospital.