Stuttgart 21, the plan to put Stuttgart’s main station underground, was first presented to the public in 1994. The formal approval procedure began in 2001. In 2010, when construction started, the protests grew. On 30 September 2010, the police used water cannons in the palace garden, and hundreds of people were injured. The state’s premier then proposed an arbitration led by Heiner Geißler, a former CDU federal minister. From 22 October to 30 November 2010, supporters and opponents argued over the facts in Stuttgart’s city hall, and the sessions were broadcast live on television, radio and the internet. The news channel Phoenix had its second-highest ratings up to that time. A year later, on 27 November 2011, the state held a referendum on leaving the project. Statewide, 58.9 percent voted against leaving it.