Officials say they'll never know the cause of a massive fire earlier this summer that started a warehouse and then burned a wooden trestle in Metro Vancouver.
The fire sent black smoke billowing across the region, prompting an air quality advisory and the temporary closure of a bridge between Vancouver and Richmond.
Richmond Fire Rescue Assistant Deputy Chief Grant Wyenberg says the investigation has been closed, and an engineer's report found the site was unsafe.
He says the fire department cannot accurately determine the cause of the fire without being able to access what remains of the structures.
