Approaching an airport to land, at about 1,000 feet above ground level (AGL), an airliner suddenly rolled inverted, entered a vertical dive, and dove...

1. Approaching an airport to land, at about 1,000 feet above ground level (AGL), an airliner suddenly rolled inverted, entered a vertical dive, and dove straight into the ground. There were no survivors. The NTSB is unable to determine the probable cause of the crash. Is there any way for relatives of the passengers who were killed to prevail in litigation? If so, against whom? Explain.