A woman woke up "all alone" on a "cold, dark" plane after falling asleep on an Air Canada flight to Toronto.

Passenger Tiffani Adams said she woke up after falling asleep halfway through the flight to find the plane had landed and all other passengers and crew had disembarked.

The airline says it is investigating and has confirmed the incident took place.

Ms Adams described her experience in a post on Air Canada’s Facebook page, saying she had been having reoccurring night terrors since her ordeal.

She recounted how she tried to call a friend to explain what had happened, but her phone quickly died and she was not able to charge it as the plane’s power was turned off.

Ms Adams said she began full on panicking and found the walky talky things in the cockpit but realised they did not work.

The passenger then unsuccessfully tried to flash SOS signals out of one of the plane’s window using a torch.

She then opened the plane’s door and saw there was a steep drop to the tarmac below which was too big to try to jump down to.

Eventually, Ms Adams was rescued when she spotted a member of ground crew and called over to them.

Air Canada staff asked if she was okay and offered a limo and hotel, but she declined.

I haven’t got much sleep since the reoccurring night terrors and waking up anxious and afraid I’m alone locked up someplace dark, Ms Adams wrote in her Facebook post.

The airline said in a comment on the post that it was surprised and very concerned by the incident and said it would look into it.

It did not comment on how the passenger may have been overlooked.

(c) Sky News 2019: Woman wakes up alone on ‘cold, dark’ Air Canada plane after flight lands