The killing of UN peacekeepers in an IDF air strike was a "horrible thing" but Israel has done the right thing by saying it will investigate, White House press secretary Tony Snow said Wednesday. "They'll be completely transparent in the way they conduct the investigation," Snow said. "And I think that's the appropriate way to proceed." He said he would leave it to the Israelis to answer UN Secretary-General Kofi Annan's charge that the bombing was "apparently deliberate." "They've said no," Sno0w said. "But they also are exercising due prudence in making sure they do a full investigation. Something went terribly wrong." He said the United States grieves with the families of the victims and extends its condolences to them.