I don't know about other parts of the world, but in the UK, helicopters are quite carefully controlled so that they can land safely in such an event. For examp

I don't know about other parts of the world, but in the UK, helicopters are quite carefully controlled so that they can land safely in such an event. For example, to fly a helicopter over London requires pilots to fly only over well defined routes - although those with multiple engines are allowed more scope.