A vehicle collision involving two lorries near the 2km post between Kahathuduwa and Kottawa on the Southern Expressway resulted in the death of a driver's assistant and left a driver critically injured.

The Expressway Traffic Police reported that the incident occurred last night (18).

According to investigators, a lorry transporting rubber sheets from Kadawatha to Welipenna stopped on the side of the road due to a mechanical failure.

A second lorry, carrying vegetables and travelling in the same direction, subsequently crashed into the rear of the stationary vehicle.

The victim, a 48-year-old resident of Dharga Town, Aluthgama, served as the assistant on the vegetable lorry.

Both he and the driver sustained severe injuries and were rushed to the Homagama Base Hospital, where the assistant later passed away.

The vegetable lorry sustained extensive damage to its front section.

Police have taken both drivers into custody as part of the ongoing investigation.

A post-mortem examination for the deceased remains scheduled at the Homagama Base Hospital, while the Galanigama Expressway Police continue their inquiries into the circumstances of the collision.