The U.S. military is investigating a shooting incident in which four contractors from the re-named firm formerly called Blackwater are accused of killing an Afghan man after a traffic accident…The firm said it was cooperating with the investigation and had fired the four men for failing to follow regulations…The North Carolina firm, which once had a lucrative contract to defend U.S. diplomats in Iraq, has changed its name to Xe Services…"At this time, we can confirm an incident involving some of our off-duty contractors for Paravant in Afghanistan," Anne Tyrell, spokeswoman for the firm, said…She identified Paravant as a subsidiary of Xe, the renamed firm.