Two people are in critical condition and two others sustained minor injuries after an empty chair at the Crystal Mountain ski resort near Kelowna, B.C. hit a ski tower and fell about six metres causing other chairs to fall.

The accident happened around 11 a.m. PT Saturday.

'The chair was swinging and hit the tower and that was it' - General Manager Mike Morin

Crystal Mountain Ski Resort General Manager Mark Morin says the empty chair started swinging and then hit a tower, causing the line to go off the track, and  other chairs to fall.

Morin estimates the chairs were six to seven metres from the ground when the accident happened.

"What I was told was the chair was swinging and hit the tower and that was it," Morin told reporters at the scene.

Crystal Mountain ski tower

Ski tower at Crystal Mountain that was hit by a swinging chair that fell six to seven metres causing other chairs to fall (CBC/Brady Strachan)

Morin says 15 people were evacuated from the lift after the accident, none of whom sustained injuries.

"The only injuries were at the first tower, and my understanding is broken ribs, but I don't know more than that," Morin said.

However, B.C. Ambulance Service spokesperson Ben Middelsteadt  said two people were critically injured. One of them was taken to hospital by helicopter and the other critically injured person was transported in an advanced- life-support ground ambulance.

Morin says the accident involved three men and a woman between 18 and 35 years of age.  Three of them were employees of the ski resort. One was a guest. 

He says there has never been an incident like this at Crystal Mountain, which has been operating since 1965.

The B.C. Safety Authority is investigating the cause of the accident. 

Crystal Mountain has suspended ski operations pending the investigation.