Baghdad, March 5, SPA -- American troops fired on a carrushing Italian journalist Giuliana Sgrena to freedom aftera month in captivity, killing the Italian intelligenceofficer who helped negotiate her release and wounding thereporter in another friendly-fire tragedy at a U.S.checkpoint. Sgrena was discharged from a hospital in Baghdad and wason her way back to Italy early Saturday, the news agencyANSA and Sky TG24 television reported. She was expected inRome about 10:30 a.m. (0930 GMT). Prime Minister Silvio Berlusconi, an ally of the UnitedStates who has kept Italian troops in Iraq despite publicopposition at home, demanded an explanation "for such aserious incident, for which someone must take theresponsibility." U.S. President George W. Bush expressed regret and promised toinvestigate, the White House said.--SPA1126 Local Time 0826 GMT www.spa.gov.sa/244249