The aircraft was traveling at a relatively high altitude of more than 10,000 feet when the incident happened, the Wall Street Journal reported. Eyewitnesses reported seeing some objects or parts fall from the plane before it started losing altitude and descending at a steep angle. BBC reported engine problems. It is unknown whether the pilot sent a distress call before the crash. Three people, among them the pilot, managed to jump out the plane with their parachutes and survived with only minor injuries, according to the Wall Street Journal. The plane caught fire after impact. All others on board were killed. Police have yet to identify the victims, but according to reports they were experienced skydivers from the city of Tampere. The three survivors are being treated in a local hospital for minor injuries. Investigators are now trying to understand the cause of the accident. According to Ismo Aaltonen, an investigator with Finland's Safety Investigation Authority quoted by the Wall Street Journal, this is the most serious flight accident in decades in Finland.