As rescuers in Elliot Lake worked frantically to reach people trapped in a mall collapse, experts from around the world were in Toronto on Tuesday to talk rescue strategy at a disaster management conference. They said time was running out for survivors who may be trapped in the rubble, but insisted there was still hope.
"I've heard, anecdotally, cases of persons who've lasted for several days in these situations, but it completely varies," said Sean Tracey, the chair of the board for the Canadian Centre for Emergency Preparedness. "The team is going to continue to monitor, listen for life signs, try and get a visual of the people they're trying to rescue."
Mr. Tracey said it was hard to predict from a distance when a decision would be made to change the mission from rescue to recovery.
"It's an on-site decision made by those individuals and it's not an easy decision," he said. "It's going to wear on these individuals and they're going to bear that burden for their lives."
The difficulty of a disaster response like this depends on a number of factors, Mr. Tracey said. They include the nature of the debris field that is blocking efforts to find survivors and how close to the collapsed area the rescuers can get without risking their own lives.
Engineers decided on Monday to halt the rescue effort because the structure was deemed unsafe for emergency responders, according to a spokesman for the search-and-rescue crews. The operation resumed, but the delay cut into precious hours that may be remaining for possible survivors, and sparked intense scrutiny from politicians and the public.
But even in much larger disasters like the 1995 bombing of a federal building in Oklahoma City, which killed or injured more than 850 people, engineers call the shots during the rescue.
Tammy McKinney, a major with the Oklahoma City Fire Department, said she was a corporal with just two years of experience when she was called to help the rescue and recovery effort. She said it is standard practice in Oklahoma State for structural engineers to travel with and advise urban search and rescue teams.
"We did not do a whole lot, really, without getting advice from [them] first for the sheer safety of our firefighters and everyone else involved," she said in a telephone interview. "Going in there and making the wrong move at the wrong time could create more havoc than do good. You could move something that was holding something else up and cause further collapse, creating more danger."
Major McKinney said engineers sometimes shut down the recovery efforts on account of high winds and the threat of tornadoes, but their advice was necessary to keep the building as safe as possible for the emergency responders. According to a post-disaster report prepared by the Oklahoma Department of Civil Emergency Management, the last survivor of the explosion was pulled from the rubble just 13 hours after the bomb went off.
Staff Sergeant Jim Bock, the unit commander of the Ontario Provincial Police's urban search and rescue team, was at the conference in Toronto on Tuesday but communicating with his team in Elliot Lake. He said more than a dozen members of the search and rescue squad were there, working with engineers to plan the best way to get at the collapsed area.
Staff Sgt. Bock said it was hard to guess the fate of those still trapped in the debris without knowing their current condition.
"What we're looking at is things like is a person bleeding, are they conscious, are they dehydrated, is there a heavy piece of concrete on them, do they have any air," he said. "We're going to do the best we can."
Peter Rekers, the owner of Crisis Ready, an Australian emergency planning company, said rescuers usually take standard steps in collapsed buildings.
"They do a thing called shoring," he said, explaining that workers brace the rubble with temporary roofs and walls so they can crawl underneath and reach survivors. "[It's] basically creating a network of tunnels in there."
Mr. Rekers, who was a speaker at the conference, said he couldn't tell without being at the scene whether anything else could be done.
"It can be a very complicated, very slow, very delicate process, but it's gotta be safe," he said. "Along with this tragic loss of life in the building you don't want to lose emergency personnel services either."