Terrain ahead . '' Transcript shows pilots warned of danger several times in about 30 seconds before crash . April crash killed Polish President Lech Kaczynski and Some 20,000 others . Delegation headed to Poland for 70th anniversary of massacre of Polish prisoners of war in World War II .
Transcript shows pilots warned of danger several times in about 30 seconds before crash . April crash killed Polish President Lech Kaczynski and Some 20,000 others . Delegation headed to Poland for 70th anniversary of massacre of Polish prisoners of war in World War II .