當日 0912 時，行車控制主任移除一班列車的行車時間表後，發現「列車控制系統」（Train Control System）的螢幕畫面未有更新，便通知車站職員安排已抵站的列車稍作停留，以便諮詢工程人員系統是否失靈
至 0925 時，由於工程人員需重啟系統，控制中心遂暫停東鐵綫的列車服務，但中央廣播聲帶亦一同中斷，故車站職員需改用現場廣播，指示乘客轉乘其他交通工具
第一部應急巴士在 0943 時由九龍塘站開往羅湖站，而由羅湖站往九龍塘站的巴士，則於 1002 時開出
已抵站的列車全數停止服務後，控制中心隨即指示車站職員，到路軌將道岔位鎖定到指定方向，以便清空月台讓停於各站之間的 14 班列車，可盡快落客
但約於 1025 時，分別有乘客逕自打開「緊急門掣」，徒步離開車廂，控制中心唯有暫停安排列車駛回月台，避免這些乘客遭列車撞到
至於 1130 時，工程人員成功啟動「列車控制系統」的後備機制，恢復東鐵綫的列車服務
經過港鐵公司與法國 ALSTOM 廠方調查後，得悉移除列車時間表的功能，附帶不常見的程式碼，導致系統記憶體耗盡。功能於 2003 年隨「尖沙咀支綫」通車，而於「列車控制系統」啟用的五年後而新增，及後於 2006 年、2009 年、2010 年、2012 年，以及 2015 年更新系統時，亦未發現問題
廠商現已更新軟件，避免出現同類問題，而東鐵綫亦預計會於 2019 年年中，改用全新 Siemens Trainguard MT 行車訊號，此前新系統會獨立運作，不會影響日常列車服務
At 0912 hours that day, Traffic Controllers found that the Train Control System displays were frozen after they have dropped the timetable for a train. They then asked station staff to keep the trains that have already berthed at platforms on hold as they verified with the engineers whether the system had failed
Eventually the Operations Control Centre decided to suspend train service on East Rail Line at 0925 hours to allow engineers to reboot the System. Meanwhile, the centralised PA was also interrupted, thus live announcements were adopted by station staff to advise passengers to use other transport
The first rail replacement bus towards Lo Wu departed from Kowloon Tong Station at 0943 hours whereas the first bus departing from Lo Wu Station to Kowloon Tong Station left Lo Wu Station at 1002 hours
After all the passengers had alighted from the trains that had already berthed at stations, the Operations Control Centre then instructed station staff to access the tracks and secure points to designated directions to enable the 14 trains that had stalled between stations to move to their closest platforms to let passengers to exit
However, at 1025 hours, various groups of passengers had operated the emergency door releases on their trains and walked on the tracks. The Operations Control Centre has left no choice but to stop some of the train movements immediately
In the end, engineers managed to resume the Train Control System and the train service on East Rail Line at 1130 hours
The investigation jointly held by the #MTR Corporation and the French signalling system manufacturer Alstom has then revealed that the timetable removal function on the System contained unusual codes, which had consumed all system memory and caused the incident. Such function was first incorporated as part of the East Tsim Sha Tsui Extension Work in 2003 and no abnormalities were found at that time, nor did they arise during the System upgrade work in 2006, 2009, 2010, 2012 and 2015
The software has now been updated by Alstom to avoid reoccurrence of similar incident. On the other hand, from mid-2019, East Rail Line will adopt the new Siemens Trainguard signalling system. The new signalling will operate independently before the full roll out and will not affect the normal day-to-day operations as a result
