Twenty people were killed when a vintage aircraft operating a sightseeing flight over Switzerland crashed into the Alps over the weekend.
There were no survivors, Swiss police announced yesterday (SUN) as a search and rescue operation was called off.
The historic Junckers Ju-52 propellor plane disppeared on Saturday afternoon after taking off from Locarno in southern Switzerland on its way to a military airfield near Zurich.
On board were three crew members and 17 passengers aged between 42 and 84 who had paid for the chance to travel on the 1930s-era aircraft.
Among the passengers were an Austrian couple travelling with their grown-up son. The rest were believed to be Swiss.
Locator: WWII vintage plane crash
The wreckage of the aircraft was found 8,330 feet above sea level near Piz Segnas in the remote and rugged mountains of eastern Switzerland.
"Based on the situation at the crash site we can say that the aircraft hit the ground almost vertically at a relatively high speed," Daniel Knecht, head of aviation at the Swiss Accident Investigation Board, told a press conference on Sunday
The cause of the accident is unclear, but investigators said they could not rule out a link to the current heatwave in Europe.
"What we can rule out at this point is a mid-air collision before the crash, either with another aircraft or with some other obstacle such as a cable," Mr Knehct said. There was no indication of any external interference with the flight, he added.
Although the Junckers aircraft was almost 80 years old, it was serviced after every 35 hours of flying time and was believed to be in good condition after its most recent service at the end of July. Both pilots were experienced and had flown for regular civilian airlines and the Swiss air force.
An investigation into the cause of the crash is likely to be complicated and take considerable time. The historic aircraft was not fitted with a black box or other modern data recording devices that could help explain what happened.
The German-made Junckers Ju-52 was first produced in 1932 and was one of the earliest civilian passenger aircraft. During the 1930s it was the most widely used aircraft type in Europe.
Affectionaly known in German as Tante Ju, or Auntie Ju, Ju-52s are chiefly remembered in Switzerland for providing a lifeline to parts of the country that were cut off by heavy avalances in 1952.
The plane involved in the crash was being operated by Ju-Air, a Swiss company that specialises in sightseeing flights using historic aircraft. It had previously been used for tourist flights in Germany.
Ju-Air said on Sunday it had suspended all operations until further notice in the wake of the crash.
"The Ju-Air team is deeply saddened and our thoughts are with the passengers, the crew and families and friends of the victims," the company said in a statement posted on its website.
In a separate incident a family of four were killed when their light aircraft crashed near Lucerne, in central Switzerland, on Saturday. The family was from the local area. Two children were among the dead.