On 26 November 1987, Krupp announced that it would close its steelworks in Duisburg-Rheinhausen. The workers learned of it from television and radio. On 10 December 1987, Krupp workers occupied the Rhine bridge between Rheinhausen and Hochfeld. That month, about 100,000 workers across the Ruhr stopped work. In February 1988, 80,000 people formed a human chain from Rheinhausen to the Westfalenhütte steelworks in Dortmund. ZDF calls the 160-day dispute the longest and hardest labor struggle in postwar German history. It only delayed the closure, and the works shut in 1993. On 20 January 1988, the protesters had renamed the bridge Brücke der Solidarität, Bridge of Solidarity. The city of Duisburg later adopted the name.