On 25 September 2024, train services on the East–West Line (EWL) of the Singapore Mass Rapid Transit (MRT) system were disrupted when an axle box on a Kawasaki C151 train dislodged, derailing the train and damaging the track and equipment between Clementi and Dover stations. This resulted in the suspension of regular services between Boon Lay and Queenstown stations, affecting more than 2 million commuters.
The damage was extensive, and services were not restored for several days. During restoration works by engineers from the Land Transport Authority (LTA) and SMRT Corporation, shuttle train services were restored between Queenstown and Buona Vista stations, and between Jurong East and Boon Lay stations. Bus-bridging services were provided for the closed segment between Buona Vista and Jurong East stations. Full services on the EWL resumed on 1 October.
This was the worst breakdown in the MRT network’s history. Investigations began on 2 October, and the LTA and the Transport Safety Investigation Bureau (TSIB) released separate findings on 3 June 2025. The LTA report concluded the failure began with degraded grease in an axle bearing, which caused overheating and fire damage to the chevron springs. This led to the detachment of the axle box and the train’s derailment near Dover station. The TSIB report added that a repair of the SMRT’s Hot Axle Box Detection System’s “Null ID” error could have identified the affected train and prevented the incident. SMRT was subsequently fined S$2.4 million (US$1.8 million)[a] and the Kawasaki C151 trains were withdrawn from revenue service by September 2025.
Background
The Singapore Mass Rapid Transit (MRT) network began operations in 1987,[3] and the stretch between Outram Park station and Clementi station opened on 12 March 1988.[4] The East–West Line (EWL) is operated by SMRT Trains.[5] The first-generation trains[b] had been running on the EWL and the North–South Line (NSL) since services began,[7] and had an expected service life of 38 years.[8][9]
Past disruptions on the MRT network include the Clementi rail accident on 5 August 1993, when an oil spill on the tracks caused two trains to collide at Clementi station, injuring 156 people.[3][10][11] On 13 April 1999, a train near Toa Payoh station derailed due to an error in track alignments.[12] A power outage at Buona Vista station led to service disruptions on the EWL, NSL and the Circle Line (CCL) on 25 April 2016.[12][13] In November 2017, a software error in the EWL signalling system caused the Joo Koon rail accident, in which two trains collided at Joo Koon station.[12][14] Twenty-eight people, including two SMRT staff members, were injured in the collision.[15] Another power outage on the EWL, NSL and CCL occurred in October 2020.[12][16][17]
Incident
At about 9:00 a.m. Singapore Time on 25 September 2024, a faulty eastbound Kawasaki C151 train (T310)[18] was pulled out of service at Clementi station.[19] Eyewitnesses reported smoke emitting from the train as it arrived at the station.[20] To return to Ulu Pandan Depot, the T310 train switched over at Queenstown station.[19][21] When the train was travelling westward near Dover station,[21] a defective axle box dropped onto the tracks, causing the bogie frame to dislodge from the third car of the six-car train.[22] The dislodged bogie caused “extensive damage” to the affected track stretch,[23] triggering a power outage at 9:25 a.m. that stalled the train.[1][21][24] The incident caused 46 rail breaks across 2.55 kilometres (1.58 mi)[c] of track,[23] and damaged the third rail, power cables, rail fasteners and point machines that enable trains to change tracks.[22]
The accident also stalled four trains between Clementi and Buona Vista, including one that was 40 metres (130 ft) from Clementi station.[24][20][25] Passengers from that stalled train disembarked and walked to Clementi station with SMRT staff guidance.[21] The train operator, SMRT Trains, reported the incident at 9:52 a.m., and suspended train services between Queenstown and Boon Lay stations.[20][25] At 2:45 p.m., the LTA announced there would be no train services between Boon Lay and Queenstown for the rest of that day because of “extensive damage”.[25][26]
Repair and mitigation works
A point machine between Jurong East and Clementi station could not be salvaged and needed to be replaced. All of the damaged equipment needed replacement, and the point machines needed realignment and careful recalibration.[22] Emergency repair works began the same day; more than 300 engineers and technicians were involved in rectification and replacement works.[27] An investigation of the incident was started.[28]
Free regular bus services were offered between Queenstown and Boon Lay stations, and SMRT Buses, SBS Transit, Tower Transit and Go-Ahead Singapore started running bridging buses between Buona Vista and Jurong East stations.[29][30] Police officers, LTA ground staff, and personnel from the bridging bus operators were deployed to manage crowds at the affected stations.[31] Shuttle train services between Queenstown and Buona Vista stations, as well as between Jurong East and Boon Lay stations, began at 3:56 p.m. and 4:11 p.m., respectively.[24] By 26 September, the shuttle train services were running at 10-minute intervals.[29] The authorities initially hoped to run a shuttle train service between Jurong East and Buona Vista by 27 September, but this was ruled out in favour of minimising delays in restoring full services. A new deadline was set for 30 September.[32] In a Facebook post, the Transport Minister, Chee Hong Tat, issued an apology for the disruption.[33]
Before moving the train back to Ulu Pandan Depot, engineers attached a temporary axle box to the T310 train and used a hydraulic system to move the wheel back onto the rail.[22] Power cables and the damaged point machines were replaced on 27 September, and repairs on the third rail were expected to be completed on the same day. During maintenance, the engineers had to use mechanical jigs instead of rail vehicles due to the broken rails.[34] The next day, the LTA and SMRT reported that their engineers had made “significant progress” with the maintenance and the completion of heavy rail delivery work. The track point machines and associated trackside equipment were replaced and tested, and the power rail was restored. On this day, an estimated 374,000 passengers were affected.[35] Once repairs were finished, systematic and functional tests – including checks on tracks, power supply and train signalling, and running trains at different speeds to ensure smooth operations – were planned for 29 September 2024.[36]
In a joint statement on 29 September, the LTA and SMRT announced engineers had found 12 more cracks, which were previously not visible, through stress and loading tests during the replacement of other damaged parts of the track. The expected reopening of the segment was postponed to 1 October after more tests were carried out on 30 September.[23][37] The next day, the LTA announced the restoration of the third rail, as well as the completion of locomotive stress tests, electric meggering tests, and track circuiting tests. Loaded-train endurance tests were still ongoing.[38] Ultrasound tests were carried out on the welds of the tracks.[39] The LTA and SMRT announced train services would resume on 1 October with temporary speed restrictions on westbound tracks for safety. Train speeds would be reduced from 60-to-80 km/h (37-to-50 mph) to 40 km/h (25 mph) for safety.[39][40][41] Trains resumed running at full speed on 5 October.[42]
Impact
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According to CNA, The Straits Times and South China Morning Post, the incident was the most severe disruption to the MRT system in its history.[42][43][44] The disruption caused significant increases in travel times; The Straits Times reported that a typical journey from Jurong East to Redhill took approximately 90 minutes instead of the usual 21 minutes. Queues at bus stops serving the affected stations were as long as 100 metres (330 ft).[31][45] Many commuters were confused by the transport arrangements, such as the location of free bridging bus stops for closed stations.[31] Some voiced their frustration about the disruption and its spillover effects, including the longer travel time and the long walking distance between Jurong East station and its associated bridging bus stop.[45][31]
The disruption was estimated to have affected more than 2.1 million commuters as of 30 September,[44][46] including 358,000 passengers on the first day, 516,000 passengers on the second day, and 500,000 passengers on the third day of the disruption.[35] Passengers alighting at stations between Boon Lay and Queenstown were not charged, and bridging and regular bus services were provided for free.[21] Overall, 2.6 million commuters were affected before services were restored.[42]
The incident occurred during the Primary School Leaving Examination (PSLE). In response to the disruption, the Ministry of Education (MOE) announced students taking the PSLE on 26 September were granted the full allocated time to sit their paper as long as they arrived before the end of the exam.[47] Free taxi services were offered to ferry students to their examination venues from affected stations,[48][49] though according to The Straits Times, the students did not use taxis.[50] Five students were late for their papers on 26 September, with one student taking the examination in a different examination centre.[47] According to the Singapore Examinations and Assessment Board (SEAB), no candidates were affected by the disruption for the mathematics exam on 27 September. On 30 September, the SEAB reported that seven students were late for their papers on that day.[51]
Regulatory and parliamentary response
On 2 October 2024, representatives from public bus operators and the LTA met to discuss their management of the bridging bus services during the disruption and to examine improvements needed for such incident-management plans.[30] In 2025, CNA reported that SMRT’s recovery efforts cost more than S$10 million (US$7.5 million).[52] On 1 November, SMRT announced the establishment of a tripartite workgroup consisting of representatives from the LTA, SMRT, and the National Transport Workers’ Union that would oversee the reliability and safety of the rail network.[53][54]
Thirty-seven parliamentary questions regarding the incident were filed for the Transport Minister Chee Hong Tat,[55] of which 19 were answered on 14 October.[56] Chee summarised the circumstances of the incident in his ministerial statement, saying some details would only be confirmed after investigations were completed.[57] Addressing questions on fare increases, he said service levels and disruptions are not considered in the Public Transport Council‘s (PTC) fare-review exercise, which is focused on financial sustainability and changes in operating costs. Reliability is managed separately through penalties and incentive schemes. Chee also said SMRT would bear all costs arising from the disruption, including free transport services, lost fare revenue, and repair works, and that affected staff would be compensated for overtime.[21][58]
