Helicopter CRASHES into house sparking deadly fireball killing 4 defence plant workers as vid shows wreck burn in Russia

A HELICOPTER has crashed into a house and exploded into a huge fireball leaving four defence plant workers dead. Horror footage shows the wreckage of the Ka-226 chopper as it burns before firefighters arrived at the scene desperately trying to extinguish the flames. The helicopter was carrying senior staff from Kizlyar Electromechanical Plant in Russia…