SkyTrain commuters got a bit of a scare when a door slid open while the train was still approaching Edmonds Station in Burnaby, B.C. on Wednesday morning.

The incident was witnessed by CBC News intern Zahra Premji, who alerted TransLink on Twitter. She said the door opened about 20 to 30 centimetres — before the train began slowing down for the station.

The incident surprised those on board, who stepped away from the partially open door, which then closed on its own several seconds later, said Premji.

TransLink spokesperson Jennifer Siddon said they've taken the train off the tracks so they can determine the nature of the problem.

"What we're trying to determine is whether this was a passenger leaning up against the doors and they opened that distance, or whether there's actually a problem with that train in particular. And that's what we're investigating right now," she said.

Siddon says the doors can open up to 10 centimetres in case of an emergency.

Have you seen SkyTrain doors open between stations, or witnessed a similar incident? Email cbcnewsvancouver@cbc.ca