National Transportation Safety Board (NTSB) investigators will probe the wreckage and the site of a helicopter crash in Northern California where eight firefighters and the co-pilot are feared dead. The Sikorsky S-61N helicopter (N612AZ), operated by the U.S. Department of Forestry, crashed Aug. 5 after picking up the firefighters from a remote wilderness in Northern California in the evening to shuttle them to another hotspot. It crashed after takeoff and a post-crash fire ensued. Local reports said three firefighters and the pilot were hospitalized at Mercy Medical Center in Redding and the University of California Davis Medical Center with serious burns. The firefighting helicopter was owned by Carson Helicopters, based in Grants Pass, Oregon. The crash site is in a remote, forested area roughly 35 miles northwest of Redding. A spokesman for Carson Helicopters reportedly said preliminary indications suggested that neither weather nor visibility should have played a role in the fatal crash.