Lee Jia Jun was struck by a falling tree branch on 20 July 2016 as he was riding on his motorcycle to his workplace at Woodlands Loop.
The 24-year-old Malaysian suffered severe head injuries which have left him in a vegetative state.
His wife and sister have since sued Nparks for negligence.
Acting on behalf Lee as he is presently mentally incapacitated, the pair claim that the accident was caused by NParks’ negligence in failing to reasonably maintain the trees in a healthy and stable condition so as not to pose a danger to road users.
In addition to that, they accuse NParks of failing to conduct adequate crown reduction pruning exercises to limit tree exposure and damage from adverse weather conditions.
The lawsuit is a landmark case as it could clarify the extent of NPark’s liability in such cases.
Lee, who has a 2-year-old daughter, was riding to work when he was hit by the falling tree branch.
He was flung off his motorcycle and suffered head injuries.
He continues to receive treatment in Ipoh where he remains in a vegetative state.
NParks, in its defence, says that said there was a system in place to assess the condition of the trees along Admiralty Road West including regular inspections, and maintenance works were carried out on trees along the road.
The agency said that the tree was healthy and the cause of the tree branch breaking was likely to be exposure to unusually stormy weather for days leading up to the incident, accompanied by wind speeds of up to 50 km per hour.
NParks added that tree inspection was conducted by an arborist on March 10 2015, followed by tree removal and pruning some three months later, while pruning was also conducted in Jan 2016.
The public has questioned NParks maintenance of trees following a series of treefalls – the most prominent of these being the collapse of Singapore’s heritage Temsbusu tree.
The Tembusus tree which uprooted and crushed to death one visitor to the Botanic Gardens was found to have 70 percent decay.