Transport operator SMRT yesterday vowed to strengthen all its security measures, even as it assists the police with investigations into the latest trespassing incident at its Bishan Depot.
On Thursday, two German men, both 21, were arrested for allegedly making their way into the depot and spray-painting graffiti on a train on Nov 8.
How they managed to sneak in remains a mystery, but it was the fourth incident of vandalism at SMRT's depots since 2010.
Member of Parliament Lim Biow Chuan, who is on the Government Parliamentary Committee (GPC) for Transport, told The Straits Times yesterday that the repeated breaches were worrying.
"While the arrests in the latest incident give some comfort, it would be better if we can make sure that people can't just break in and do anything at the train depot," he said. "Today we have young people doing vandalism, tomorrow it may be someone else with a more dangerous intent."
MP Vikram Nair, who sits on the GPC for Home Affairs and Law, expects the police to look into how the latest security lapse occurred at what is "obviously a sensitive installation".
Transport GPC member Ang Hin Kee said it was too early to start pointing fingers and recommending changes, before investigations are completed. "Knowing the cause of the breach may provide some clue as to what needs to be done," he said.
The first depot breach occurred at SMRT's Changi installation in May 2010, when two vandals cut through the wire fence and spray-painted graffiti on one side of a train. Swiss national Oliver Fricker was given seven months' jail and three strokes of the cane, while Briton Lloyd Dane Alexander remains at large.
Then in August 2011, a hole was cut in the wire fence at Bishan Depot, and the words "Jet Setter's" spray-painted on a train. No one has been caught yet.
Since those incidents, for which it was fined $250,000 in total, SMRT had put in intrusion detection systems, increased patrols and switched its security contractor twice, going with Evtec in place of Ademco in 2010, and then hiring Certis Cisco in 2012.
Yet in May this year, a train was found in Bishan Depot with large surfaces of a carriage smeared in red, with smudges of white and green. Six months later, another train was vandalised.
"We are mindful of public concern... We have in place a set of measures such as interior and exterior checks of trains to detect any suspicious object or activity," said SMRT vice-president Patrick Nathan. He added: "SMRT is working with the relevant agencies to strengthen all security measures in place."