Complex sentence: Lothar Sieber (born 7 April 1922 in Dresden; died 1 March 1945 at Lager Heuberg) was a German test pilot who was killed in the first vertical take-off manned rocket flight, in a Bachem Ba 349 "Natter".
Split into simpler sentences: Lothar Sieber (born 7 April 1922 in Dresden; died 1 March 1945 at Lager Heuberg) was a German test pilot. He died in the first vertical take-off manned rocket flight in a Bachem Ba 349 "Natter".