https://www.hongkongfp.com/2017/02/10/breaking-mtr-rush-hour-chaos-four-injuries-fire-breaks-train/
Though the possibility of terrorism is very low in Hong Kong, sudden arson by a citizen can happen. (The reason why Hong Kong has low possibility to cause terrorism is that there is no country conflicting politically with Hong Kong. Surely, many citizens in Hong Kong dislike Mainland China. But, it doesn't drive them into carrying out terrorism in their own country)
Fortunately, MTR Island Line doesn't have flammable seats on trains, which are made of stainless.
To ensure safety, other railway companies have to change seats to stainless ones?