I remember many years ago a news chopper (Australian Channel 7 B206) was hovering at 700ft in a built up area filming some incident when it became the spectacle when the engine stopped. Perhaps the pilot in some forethought had already picked an emergency spot to land before positioning himself in the high hover, as you would expect. There is dramatic footage of the helicopter going nose steeply down in a spiral dive (some here would call it tumbling) before disappearing behind a building. He landed in a small car park. Pilot and crew walked away. This exceptional feat occurred in broad daylight. It would be extremely challenging to pull off a similar successful landing using this technique in a built up area at night.