the german president, frank valter schtinemeier, has asked for poland's forgiveness at an event marking he was speaking in the polish town which was the first to suffer german aerial bombardment. our berlin correspondent, jenny hill, reports from warsaw. sudden, violent, the attacks came from air, land and sea. 80 years ago, nazi troops stormed in to occupy poland, an act of aggression which triggered the deadliest conflict in human history. air raid siren. before dawn this morning, sirens to commemorate the first civilian casualties of the second world war. german bombers destroyed the town of weilun. speaking in polish, the german president said he was sorry. translation: i bow my head before the victims of the attack on weilun. i bow my head before the polish victims of germany's tyranny, and i ask for forgiveness. in warsaw, a chance to reflect on the horrors of conflict past, but among the leaders and heads of state, two notable absences. donald trump cancelled his attendance at short notice, and the russian leader, vladimir putin, wasn't invited. the leaders who came here today ca