All crewmen were killed in a Mi-8 helicopter crash in the Tula region (Central Russia).
The Mi-8 helicopter crashed at 11.36 Moscow time near the village of Buldanovo (Tula region) during a planned flight, Colonel Alexander Drobyshevsky, spokesman for the Russian Air Force, told RIA Novosti.
In his words, rescuers found the bodies of three Mi-8 crewmen. "The search for the forth man is in progress," Colonel Drobyshevsky said.
According to preliminary data, the helicopter's icing caused the tragedy.
"The helicopter entered the icing area at the height of 3,000 meters, went out of control and fell on the ground," a source in the Tula law enforcement bodies told RIA Novosti.