Eighteen people were killed in a Russian helicopter crash on Saturday in East Siberia region, authorities said.Russia's Emergencies Ministry said the MI-8 went down at 10.20 a.m., about 180 kilometre from the town of Igarka, in Krasnoyarsk region."There were three crew members and 15 passengers abroad the Mi-8 that belonged to Utair airline," an emergency services official told TASS news agency. The helicopter flew 2 kilometre before it crashed. No one survived.According to preliminary data, the helicopter collided with the external cargo suspension of another helicopter that took off earlier, before it fell, collapsed and burnt, a statement published by Russia's Federal Air Transport Agency said.The helicopter with cargo landed safely after the crew dropped the external suspension, it added.Law enforcers said that all possible versions were under consideration, including a crew error and equipment failure.A task force was set up to establish the causes and conditions of the catastrophe. The criminal investigators of the Main Directorate of Criminalistics of Russia's Investigative Committee were sent to the scene, the committee said in a statement.Both black boxes of the helicopter were found, a source in regional emergency services was quoted by Sputnik news agency as saying, adding that the recorders were in a satisfactory condition.The Emergencies Ministry was sending over a group of An-74 and Be-200 aircraft and 25 people from regional search and rescue centres to the site of the crash, according to the Krasnoyarsk region branch of the ministry.