An RCMP crash reconstructionist has shed some light on what happened to a bus full of University of Victoria students in mid-September.

The bus, travelling to the Bamfield Marine Sciences Centre, moved over for an oncoming vehicle as the road narrowed and rolled, killing two UVic students.

RCMP Sergeant Brian Nightingale said police used a 3D scanner and the event data recorder on the bus to figure out what happened.

The road narrowed from 10.8 metres to 9.2 metres and while the bus still had enough room to get through, the driver made an adjustment at the same time the road narrowed.

The bus hit the soft shoulder on the gravel road, rolled onto its roof, coming to rest three metres below the road.

Two students from Winnipeg, Manitoba and Iowa City, Iowa were killed.