Sept. 9 (UPI) -- A recently released transit video, showing last month's deadly stabbing of a Ukrainian refugee on board a Charlotte, N.C., light rail train, has prompted the U.S. Department of Transportation to investigate her murder and consider withholding federal funds until public safety is improved. Transportation Secretary Sean Duffy announced Monday night his department "will be investigating Charlotte over its failure to protect Iryna Zarutska." "If mayors can't keep their trains and