A small earthquake that struck Basel on Friday was caused by drilling work for a planned power plant that would produce electricity from heat in the Earth's crust. The canton Basel-City prosecutor has launched an investigation to find if the company behind the Deep Heat Mining project can be held responsible for any possible damage. The tremor was felt shortly before 6 pm and measured 3.4 on the Richter scale according to the Swiss Seismological Service. The local police and fire departments received hundreds of phone calls from worried citizens, and some buildings suffered from cracks and broken tiles....