5th set of human remains found at industrial explosion site in south Ottawa

Investigators have found a fifth set of human remains at the Eastway Tank explosion site in south Ottawa, but the hazardous terrainis still making it too treacherous to reach the remains and begin the process of identification, a supervising regional coroner says.

"I can't give you an exact amount of time," saidDr. Louise McNaughton-Filion, the coroner overseeing the Ottawa and eastern Ontario regions, on Monday afternoon.

"I can tell you that the work is going to be intense. People are going to be dedicated to getting this done as quickly and as well as possible."

An explosion last Thursdayripped through theMerivale Road headquarters ofEastwayTank, Pump and Meter Ltd., a manufacturer of tanker trucks.McNaughton-Filion's office is focusedon determining how people died and how deaths such as theirs can be prevented in the future.

The Ottawa Police Service has said one person taken to hospital died, while five other people believed to have beenin the building at the time of the blastare presumed dead.

McNaughton-Filion's disclosure of five sets of remains foundis up from the four announced at thelatest investigation briefing this pastSunday.

'Not a typical scene'

While the total number of remains located so far matches the number of missing people cited by police,McNaughton-Filionsaid investigators haven't discounted the possibility someone else's body is amid the rubble.

"We don't have any evidence for that right now," she said."But we have to be careful that we are thorough to make absolutely certain that we find what is to be found at the site."

McNaughton-Filion cited pressurized gasses, cold working conditions,and the potential for frozen and fragile evidence as some of the challenges and hazards facing workers combing through the scene.

"This is not atypical scene that we would go to. This oneis much more complex and we have to make sure that, numberone, we do not lose evidence,and number two, we protect the people that go to the scene."

She's not the first official to emphasize the difficult working conditions and their effect on the pace of the investigation.

"It's going to take some time to thoroughly sift, systematically," saidTim Beckett, Ontario's deputy fire marshal, at themedia update held Sunday. "It's not fast."

After they're found

Once investigators can actually retrieve the remains "in a very careful manner and very respectful manner," there are a number of ways to identify them, including dental records, fingerprints, and DNA samples,McNaughton-Filionsaid.

The mother of Danny Beale, a 12-volt electrician among the five Eastway workers presumed dead, previously told CBC News she had been asked to provide a blood sample. She said she also gave other information about her son's surgeries and cheek implants.

"There are different sources of DNA,"McNaughton-Filionsaid.

"We can get DNA from swabs from the inside of the mouth, from blood, from tissue, from bone. It is possible to get it from teeth."

Several types of specialists will become involved in the investigation very soon, she added.

"Forensic pathologists are a key part of our team. Forensic anthropologists arealso people that help us. Forensic odontologists are people that look at the dental [evidence] and also the people at the Centre for Forensic Sciences who help us with DNA."

Telling families all at once

Police have not identified any of the missing people presumed dead, though CBC News has independently verified their identities: Rick Bastien, Etienne Mabiala, Danny Beale, Kayla Ferguson and Russell McLellan.

McNaughton-Filionsaid her officewill only confirm the identity of people's remains to families once all of the remains have been identified.

"When there's more than one person who has passed away and we are identifying them, we want to confirm the identity of everyone."