“The chair crash is related to a tensioned winch rope of a snow groomer. A four-seater chair collided with the rope on the descent and then fell about 10 meters into the depth.”
Yesterday evening shortly after 10pm local time a quad chairlift crashed from a height of 10 meters while on descent from the upper section of the Stoos-Fronalpstock in central Switzerland.
Sz.ch is reporting a 33-year-old woman and a 40-year-old man suffered life-threatening injuries in the crash and were airlifted to hospital. Two other men suffered less serious injuries. Six other people were on other chairs at the time of the crash and were safely evacuated. 
Initial investigations are showing the chairlift haul rope came in contact with a tensioned winch rope from a snow groomer causing the accident (the type used to assist grooming in steeply pitched areas). All ten people on the chairlift at the time of the incident were employees of the Lindt Chocolate company and were on the way down from a company event. We will be sure to update this story as news comes in.
Nach dem Absturz eines Vierersessels am Fronalpstock sind zwei Personen lebensbedrohlich und zwei erheblich verletzt. Erste Erkenntnisse ergaben, dass der Sessel mit einem Windenseil eines Pistenfahrzeugs kollidiert.
Mehr Infos: https://t.co/RfaCK0PwMW pic.twitter.com/iJCS08j1zK
— Kantonspolizei SZ (@KapoSchwyz) February 7, 2020