An Air Canada plane from Toronto to Vancouver had to land early in Calgary on Tuesday night after a female passenger suffered a medical emergency mid-flight.

Passengers on board the plane say a woman went into medical distress somewhere in the skies over Saskatchewan and the flight crew made the decision to stop in Calgary to get her help.

EMS officials in Calgary confirm that a patient was taken from the airport to the Peter Lougheed Centre in critical, life threatening condition at about 11:15 p.m.

They would not confirm the age of the woman or what exactly happened to her.

After dropping off the woman, the flight resumed towards Vancouver.

Air Canada has not made any comment about the incident.