Root Causes of Fire Incidents Involving Mercedes-Benz Citaro Buses

Mr Speaker, Sir, I welcome the opportunity provided by the hon Member Mr Dennis Tan to outline the steps taken by the Land Transport Authority (LTA) in dealing with the bus fire incidents in the first half of 2026. No one was injured in the incidents, but every such fire is an incident too many.

On his first query as to whether LTA has investigated, the answer is yes. Based on the investigations, the fire incidents involving the Mercedes-Benz Citaro buses were caused by the failure of different parts. There is no indication of a common underlying cause. The parts involved were also within their manufacturer-recommended useful life.

Turning to his second and third queries, LTA directed the public bus operators to carry out additional inspections of their Citaro buses. No abnormalities were found as a result. LTA is working with the bus operators to enhance the bus inspection regime for older buses and assess whether additional preventive measures can reduce the fire risk.

Thank you, Mr Speaker. I thank the Senior Minister of State for his answers. I have three supplementary questions.

First, I would like to ask what fire detection or suppression systems are currently installed in the engine compartments of such public buses and whether LTA is reviewing the need for enhanced thermal monitoring or fire detection systems on especially the older buses to provide earlier warning of potential fires?

My next supplementary question; whether maintenance audit requirements and fault reporting standards are applied consistently across all public transport operators (PTOs)? I believe that the buses are used by different operators.

And what measures LTA takes to verify compliance and identify any gaps in maintenance practices?

Mr Speaker, Sir, in response to the first question on suppression system. It is, in a sense, related to the cause of each respective fires. For three fires that happened in the first half of this year, there were different causes. For the first incident, it involved a mechanical failure of a propeller shaft, which then became loose. As a result, the fire was caused. The second incident involved the mechanical failure of a turbo-charger.

So, the systems in place really depends on the cause that resulted in the fire. I would say that as far as the buses' electrical systems are concerned, there are indicators which will indicate the start of a fire and the bus captains would have to take the necessary steps if the bus is being used. Of course, beyond that, we have the maintenance regimes and each manufacturer would indicate the service length or time for each parts that is being used.

Moving on to the maintenance regime of these buses, indeed, the Citaro buses would have a certain manual that has to be complied with and LTA's expectation would be that the manual for the maintenance must be followed.

On the third point about audits, I would say that for the three cases, LTA has not just been in contact with the PTOs, but has also been in contact with the manufacturer – in this case, Mercedes-Benz. They have also come in to check the systems and they have found no abnormalities which may have a system-wide impact. We are continuing to monitor the situation and will not hesitate to take any further steps necessary to maintain passenger safety.

I am obliged to the hon Member for his clarification. I can confirm that there are fire suppression systems available for the engine compartment. But as to the specifics, I do not have the details at this point in time.