The "right thing to do" - that was how Minister for Home Affairs and Law K. Shanmugam described the closure of Hougang MRT station due to a security incident on Sunday.
Recounting the events that led to the station's closure, Mr Shanmugam told the audience at a security conference yesterday that a station camera had picked up someone leaving a bag behind and walking off.
"The immediate response was to close the station down," he said in a half-hour speech at the opening ceremony of Milipol Asia-Pacific 2017 at Marina Bay Sands.
"There were questions as to whether we overreacted," he added, "but if it were really a bomb, then the question would be why we did not, so closing it was the right thing to do."
In his speech, Mr Shanmugam talked about the evolving threat of terrorism, pointing out terror group Islamic State in Iraq and Syria's rhetoric that "anything can become a weapon", and what it means for security.
This calls for collaboration with like-minded countries, the private sector and industry to develop technology such as artificially intelligent surveillance cameras, and to nurture a pool of technologically savvy officers, he said.
"It is going to require a fundamental change in the way security agencies think and operate because they have to keep trying to stay ahead of the terrorists."
Referring to a report by The Straits Times (ST) on the 20-minute closure of Hougang station, Mr Shanmugam highlighted the SGSecure mobile app as one such tool. An SGSecure user quoted in the report told ST that he had received an alert on the app urging the public to stay away from the station.
Launched by Prime Minister Lee Hsien Loong in September last year, SGSecure is a national movement that seeks to sensitise, train and mobilise Singaporeans in preventing terrorism and dealing with its aftermath.
"There is a general sensitisation to this idea," Mr Shanmugam observed on the uptake of SGSecure. The app has received 380,000 downloads.
He said that it was the Government's duty to ensure that SGSecure becomes part of the national fabric, and that it intends "to go to every single household in Singapore (to do so)".
"We have done (this for) about 60,000 households since we started," he said, adding that every household in Singapore would be reached over the next three years.
In the incident at Hougang station, a 39-year-old man who left the bag unattended at the platform was arrested for causing public nuisance. The Straits Times understands that he is currently out on bail, pending police investigations.
On the station closure, experts at the conference agreed that it was better to be safe than sorry.
Professor Alexander Siedschlag, who conducts homeland security research at Pennsylvania State University, told ST that the authorities needed time to make a comprehensive assessment on whether there was a threat.
"They needed some time to consider the situation... see if it is part of a bigger picture... (and) if there are suspicious things happening (elsewhere) in the country and in the transportation system," he said.
Still, Prof Siedschlag cautioned against regularly shutting down vast swathes of transport infrastructure. "It should not become a habit, where you have to do it every other day," he said.
He emphasised the need to leverage technology, training and reporting systems to find solutions that reduce disruption without compromising safety.