A Transportation Safety Board report says a small plane that vanished in British Columbia's Fraser River last June hit a power line before sinking into the river.
The Cessna 172M left Boundary Bay Airport on June 6 with two men aboard, an instructor and his student.
The report says the plane was flying in Abbotsford, B.C., along the river at a low altitude and was just 38 metres above the water when it clipped a power line.
Witnesses who called 911 reported seeing a low-flying plane, a splash and then the partially submerged plane on the river.
When emergency responders arrived, the plane had disappeared and a search over several months using divers, underwater imaging and other equipment has found no trace of the plane or its occupants.
The report's conclusion says low-altitude flight always presents a higher risk with hazards, such as power lines that aren't physically marked, difficult to see in time to avoid a collision.