The March 1933 elections saw great gains by the National Socialists to seats of power, both on the state and national level. On February 27, 1933, six days before the election, the Reichstag was burned, an event that was blamed on the Communists. With Nazis in key positions in government, Adolf Hitler was able to push through the Reichstag Fire Decree, which was then signed into law by President Paul von Hindenburg. The decree withdrew civil liberties and enabled the Nazis to arrest anyone they deemed to be an enemy. This became first and foremost a confrontation with the KPD, but in effect, outlawed all political parties in Germany, other than the Nazi Party. The Enabling Act of March 27, 1933 consolidated their power and authority. By the end of April 1933, the Nazis had arrested 18,000 Communists, 12,000 SPD members and others, filling concentration camps. By June 1933, more than half of the KPD's district leaders were in detention and hundreds of Nazi opponents had been killed. Many people went underground, including Jacob.