Helicopter crash kills Nicaragua air force chiefs 21 June 2013 Last updated at 09:55 Key members of Nicaragua's air force, including the chief of staff, are among 10 people killed in a helicopter crash. The helicopter was returning from a military base in the north-west when it came down near a lake west of the capital Managua. The cause is unknown. Air force Chief of Staff Colonel Manuel Lopez was killed in the crash, the Nicaraguan army said. The air defence chief and the head of air force counter-intelligence were also among the dead, the army said. The soldiers had reportedly been at a training session in the north-west town of La Paz Centro and were returning to the capital when the crash happened. Army officials said an investigation was under way.