The fatal accident that sparked the Dec 8 riot in Little India happened when Indian worker Sakthivel Kumaravelu, 33, fell into the path of a left-turning bus.

The bus later had to be jacked up in order to extricate the body, a reconstruction expert testified on Wednesday, on the first day of the Committee of Inquiry (COI) hearing into the matter.

Dr Michael Tay, a senior consultant forensic scientist, said he was engaged by the Traffic Police to determine the driver's line of sight and blind spot, the speed at which the bus was moving at, as well as the point of collision, and to reconstruct the accident based on scene photographs and other available information.

He told the court that some of the tools he relied on to determine the speed of the bus included the lane markings on Tekka Lane, lampposts and trees that he cross-referenced with CCTV footage recorded from on board the bus itself.

Dr Tay is slated to detail his experiments with a control bus equipped with an identical CCTV system of four cameras when the hearing resumes after lunch.