Apparently they landed on the empty tank. I spoke the ATC on duty at the time, and according to the flight plan there were only 3 people onboard - that's what caused the confusion in reports.
It's extremely sad to know that if the engine failure happened on the downwind, they might've been able to initiate a re-start on the correct tank - then again, maybe the cause of the engine failure was mechanical - although I doubt it, as engines don't normally fail on approach at low power, unless it's fuel related.