Passage: Bloch was born in Ludwigshafen, the son of a Jewish railway-employee. After studying philosophy, he married Else von Stritzky, daughter of a Baltic brewer in 1913, who died in 1921. His second marriage with Linda Oppenheimer lasted only a few years. His third wife was Karola Piotrowska, a Polish architect, whom he married in 1934 in Vienna. When the Nazis came to power, they had to flee, first into Switzerland, then to Austria, France, Czechoslovakia, and finally the United States.

Question: How long did his second marriage last?
few years