Investigators in southern Germany are searching for the cause of a huge explosion in a house that left a teenager dead in a neighbouring property. The body of a 17-year-old teenager was recovered from the rubble following the explosion in a residential building in the city of Memmingen, a police spokesman said early Saturday. Rescue forces found the dead boy in a neighbouring house which was also severely damaged in the blast, the spokesman said. The house where the explosion took place and the neighbouring houses all had gas pipes connected to them, police said. “Of course this leads to suspi…