CANBERRA, Australia (AP) — A U.S. Coast Guard heavy icebreaker left Australia for Antarctica on Sunday to rescue more than 120 crew members aboard two icebreakers trapped in pack ice near the frozen continent's eastern edge, officials said. The 122-meter (399-foot) cutter, the Polar Star, is responding to a Jan. 3 request from Australia, Russia and China to assist the Russian and Chinese ships because "there is sufficient concern that the vessels may not be able to free themselves from the ice," the Coast Guard said in a statement. The Russian research ship Akademik Shokalskiy has been trapped in ice-clogged...