The National Transportation Safety Board says it was a downdraft that caused the plane crash that killed adventurer Steve Fossett after he took off from a Northern Nevada airstrip back in 2007. Investigators say an inspection of the wreckage indicates there is no sign of any malfunction or failure of Fossett's small plane. Fossett went missing after taking off from the private airstrip near Carson City on Labor Day 2007. His remains and the plane wreckage were not located until more than a year later near Mammoth Lakes, California.