British Columbia Hydro said the collapse Monday night was due to the "increased and unexpected erosion along the Fraser River due to higher than usual flows," The (Vancouver) Province reported.
Utility spokesman David Lebeter said the tower's collapse had a domino effect.
"The tower pulled down another tower inland on the other side of the [Canadian National] rail yards," and several wooden poles also topped, he said.
Power through the high-voltage system was immediately halted, and the coast guard blocked boats from the river as thick cables and 90 percent of the tower were submerged, the report said. The Royal Canadian Mounted Police also blocked off roads and highways in the area, the Canadian Broadcasting Corp. said.
Initially, some 25,000 area residents lost electricity after the 8:30 p.m. collapse, but that number was down to 4,500 by early Tuesday morning, the Province said.
No injuries were reported.