The deadly smog that has covered Delhi and its surrounding areas for the last two days resulted in a huge pile-up of vehicles on the Yamuna Expressway in the capital's outskirts this morning. At least 24 vehicles were damaged and several of the drivers were injured, sources said. The driver of a truck, severely injured, was extricated from the vehicle with great difficulty by the locals. He has been admitted in a nearby hospital. Several other drivers were released after first aid.