A helicopter crashed in Russia's western Kostroma region on Tuesday, killing one person and leaving four others injured.
A Mi-2 helicopter on a medical evacuation flight crashed some 4 kilometers (2.5 miles) away from Kostroma Sokerkino Airport, the state-run TASS news agency reported, citing emergency service officials.
"There were five people: two pilots, two medics and a patient onboard. The patient died in the crash and the four others were hurt," the official said, adding that the survivors are in "serious condition."
Preliminary findings suggest the crash "might have been caused by a technical malfunction or piloting error," according to the report.
