All 17 passengers and three crew members died in the crash, which happened around 5 p.m. local time. They were aged between 42 and 84.
The plane, which was on a flight between Locarno in southern Switzerland, to Dübendorf, a suburb of Zurich, was found about 2,540 meters (8,333 feet) above sea level.
The cause of crash is now being investigated by the Federal Prosecutor’s Office, in partnership with local Swiss authorities.
Operator JU-Air has now suspended all flights until further notice. “The JU-Air team is deeply saddened and thinks of the passengers, the crew and families and friends of the victims,” the company said in a statement on its website.
Two crashes in one day
In a separate incident on Saturday morning, another small plane crashed near the town of Hergiswil, in central Switzerland, killing all four family members on board.
The wreckage was discovered engulfed in flames, and the cause of the crash is now being investigated by the Federal Prosecutor’s Office, in cooperation with local Swiss authorities.