A judge has refused to lift a temporary restraining order that would have allowed for the demolition of a Lowell apartment building that burned down last week, killing seven tenants.

The city and the building's owner want the building torn down, citing public safety and health concerns, now that a state investigation has determined that the three-alarm blaze was caused by an electrical accident.

But lawyers for the families of some victims say private fire investigators are still combing through the rubble, looking for additional clues. The Sun (http://bit.ly/1nixrvs ) reports that those investigators should be done by the middle of next week and demolition could begin next Thursday.

The judge, citing the number of victims, on Thursday said ``We need to find out what happened.'' About 60 other tenants were displaced.