By TOM KRISHER
AP Auto Writer
DETROIT (AP) — A second person has been killed by an exploding air bag inflator made by a Tennessee company that has been under investigation by a federal agency for more than six years without any resolution. On Wednesday, the National Highway Traffic Safety Administration posted recall documents filed by General Motors that revealed the second death. An air bag inflator made by ARC of Knoxville that was in a 2015 Chevrolet Traverse SUV blew apart, spewing shrapnel and killing the driver. Safety advocates say the safety agency has taken too long to finish the investigation into the ARC inflators. Messages were left seeking comment from the federal agency and ARC.