Police say the search for two Woodstock residents still unaccounted for after an explosion and fire at an apartment complex could take days.

The names and ages of the two people who remain missing have been confirmed by police, and they say the prospects are grim.

Margaret Gillett, 73, and 79-year-old Bill Watmough, both lived in the building and their families have not heard from them since the explosion.

The Ontario Fire Marshal's Office, OPP Urban Search and Rescue, Woodstock fire and police continue to work at the scene.

But it could be next week before crews determine whether or not there are bodies in the rubble of the burned out building.

Heavy equipment is being used to move heavier debris, and additional searches are being done by hand more carefully in one critical area on the east side of the debris field.

Bill Hiscott of the Ontario Fire Marshal's Office says "That is where we have an indicator, with background information…we've been able to pick together as to where the possible location of the victims may be."

The cause of the blast has not yet been determined, but police say there is no indication of criminal activity.

Police are also asking anyone who captured video or still images of the incident, that have not yet spoken with investigators, to contact 519-537-2323.

Families thinking of loved ones

The daughter and granddaughter of Margaret Gillett describe her as a caring, loving woman and say they are still trying to come to terms with what has happened. She had three children and seven grandchildren.

Daughter Deb Tamburri says it's "It's going to be the hardest thing once we find out if it's her, I don't know, it's not real. It hasn't hit me yet."

Granddaughter Jaynee Gillett says "Our Christmas that we just had was really good, so I just keep thinking of our Christmas together, and the last conversation I had with my grandma."

Gillett lived in a second floor apartment in the central section of the building that collapsed.

Lawyers meet with building tenants

Meanwhile about a dozen tenants turned out for a meeting held by lawyers preparing for a possible class-action lawsuit.

Lawyer Sharon Strosberg says "Our position will be they're entitled to be compensated for the act of the evacuation, for the intendent injuries, for the emotional distress, for lost wages if they're unable to go to work."

Building resident Rob Earl says "I don't really care about the stuff that's in the apartment, I really don't. I got out, I got family. I just worry about the other people that didn't have insurance and that."

With files from The Canadian Press