Editor's note: This story has been updated to reflect news events.
The Friday lockdown of Boston and surrounding communities was a highly rare response in the United States to a terrorism threat, reminiscent of security plans typically contemplated in response to attacks involving weapons of mass destruction, according to homeland security specialists.
Massachusetts Governor Deval Patrick urged Boston-area residents to “shelter-in-place” while the manhunt for the surviving suspect in the Monday Boston Marathon bombings continued. Suspected bomber Dzhokhar Tsarnaev was captured alive Friday night. The 19-year-old and his older brother, who was killed early Friday morning during a shootout with police, are believed to have planted bombs on Monday that killed three people and wounded more than 100 others at the Boston Marathon.
Mass transit in Boston was halted and area universities were closed, with students directed to remain indoors. Local businesses were asked not to open; city schools were shut down; and city workers were told not to come to work or, if already at work, to shelter where they were, according to NBC News.
The idea of staying in place is a disaster response procedure that heretofore has largely been reserved for use in response to a WMD attack or incident involving the release of chemical, biological, nuclear materials or a weather emergency such as a tornado or snow storm.
“Shelter-in-place means selecting a small, interior room, with no or few windows, and taking refuge there,” according to an American Red Cross fact sheet. Individuals are advised to maintain a connection with the outside world via television or radio so they can be updated by local authorities on the evolving security threat and receive any new safety precautions.
“Wherever you are, it doesn’t have to be home, we are asking you to stay where you are until the conditions improve,” Chris Geldart, director of the District of Columbia’s Homeland Security and Emergency Management Agency, said in a Friday interview in describing shelter-in-place.
Frank Cilluffo, director of the Homeland Security Policy Institute at George Washington University, said he did not know of any other circumstances when a city-wide lockdown of an area as big as Boston was implemented in response to a security threat.
“Clearly this is, in terms of scope and scale, extraordinary but the circumstances are extraordinary as well,” he said in a Friday phone interview.
During the three weeks that the Beltway sniper attacks took place in October 2002, residents in Washington and neighboring areas of Virginia and Maryland were advised to be cautious, but no city-wide shutdowns took place even as John Allen Muhammad and his accomplice, Lee Boyd Malvo, gunned down people at random.
More recently, the February manhunt in California for Christopher Dorner, whose shooting spree killed four people, was a massive undertaking by area law enforcement agencies, but never required the shutdown of entire cities.
Cilluffo said the unique circumstances involving the hunt for Tsarnaev likely led Boston officials to make the safety call they did.
“You’ve got an imminent threat here," he said. "You have an individual who already has been involved in terrorist activities.”
Cilluffo added: “The first priority is always public safety."
Another Homeland Security Policy Institute expert, Christian Beckner, agreed: “It’s rare to have this sort of suspect who is so actively armed and clearly intent on carrying out either more shootings or blowing stuff up before he gets caught -- and probably not looking to be caught alive at the end of this.”
Having the public remain indoors and out of harm's way frees up more police resources to search for the suspect, according to Beckner, who is the institute's deputy director. A suspect could more easily go undetected were he in the presence of day-to-day crowds on busy city streets.
“That kind of decision on what they did today is based on the facts that they have on hand and the fact that they clearly had information that this was going to be something that played out in the public arena," Geldart said. "So they didn’t want to have folks out here in harm’s way."
Given that Washington is considered to be one of the top U.S. cities at risk of terrorist attack, the city government has done considerable emergency planning in recent years regarding how to respond not only to a WMD attack but also to lower-level terrorist threats, according to Geldart.
It would depend on the specific circumstances surrounding the terrorist danger to determine what the public safety response would be for the city, said Geldart, adding a decision could be made to direct one area of Washington to shelter-in-place while urging other areas of the city to evacuate.
“We’ve worked very hard with our government entities and the private-sector entities inside D.C. to work on that shelter-in-place policy,” the city official told Global Security Newswire.
Keeping a shelter-in-place order for longer than 24 hours, though, would become “very very difficult,” Geldart acknowledged. Affected individuals might have health needs that require them to leave their sheltering space or they could run out of necessary supplies.
Experts emphasized the importance of having emergency plans in place before a disaster strikes that could include things such as water or emergency rations.
In the event of a security threat or massive weather event, the District of Columbia has a number of mechanisms in place for alerting the public to the danger they face and safety precautions to take. These mechanisms include alerts that residents sign up to receive via text message or e-mail. The city government also uses Twitter and Facebook to push out public awareness messages, and has preexisting agreements with local news organizations for disseminating critical public safety information.