Charlottetown fire officials say they have completed the on-site work needed for their investigation into the March 29 fire that claimed the lives of three Island teens and left another with injuries.

Fire inspectors have spent nine days in the abandoned building on Mount Edward Road taking photos, sifting through debris and getting measurements.

Fire officials have turned control of the building over to police, who hope to return it back over to the owner as soon as possible.

Tim Mamye, deputy fire chief, said Monday evening was the last time fire officials will visit the site. Now, they will begin compiling information.

“Then we determine what we can as far as a cause and an origin. And we are focused in an area of origin right now. And as far as the cause, we haven't quite determined that yet.”

Meanwhile, fire officials have received counselling to deal with the emotional impact of the tragic fire.

Brandon MacKinnon, Joseph Allison Reeves and Kenneth Irving died in the fire.

Police have not spoken yet with the surviving boy who remains in hospital.