Such was the demand that a second open day was arranged on August 11-12.\r\nThe new tunnel is 4km long and will have four underground stations including one beneath the main station. The project was approved in 2000, but the official ground breaking did not take place until July 9 2003, with the main construction work starting in 2005. Construction problems coupled with the tightening of safety requirements following the collapse of a section of tunnel for the Cologne U-Bahn have increased the cost of the project from the original estimate of \u20ac572m to \u20ac960m. The state of Saxony is responsible for funding the additional cost.\r\nWhen the tunnel opens there will be a major expansion of S-Bahn services which will be organized as a 442km six-line network serving 100 stations in the Leipzig area. It is planned to operate 12 trains\/hour through the tunnel using a fleet of 51 Talent II emus.