MRT vandalism

In the case of MRT train being vandalized. so far only a 33 year old Swiss national has been arrested. The police are still investigating and arresting people who were involved in the vandalism.
Vandalism destroys the aesthetic beauty of something. By vandalizing, these people are being very inconsiderate. There are many other people using the MRT train. Should these vandals not think about the users? Besides, there vandalism would mean that the train company have to spent money and resources clearing up the mess that they made. When the train is pulled out of service for cleaning, if the company does not have another train to replace the one out of service, then it would cause a lot of trouble for the commuters.
These vandals do not understand how the electronics work. When they trespassed and vandalized the train, what if they had damaged a piece of important equipment. If that happened, it might put a lot of people in danger. If the train malfunctioned, it might cause a tragedy, leaving many injured or even worse, dead.
The MRT staff should also be blamed for this incident. When the vandals had trespassed, why didn't they notice it. If those who had trespassed were not vandals but terrorist, they could have planted a bomb and the consequences would have been disastrous. Also, the staff did not notice the vandalism for two days. The train went in and out of the station and none of the staff noticed it. I feel that the MRT staff should be more alert and aware of their surroundings. This incident has shown that the staffs were not vigilant enough. This time it is vandalism, who knows what will happen the next time due to the staffs' lack of vigilance.