Flags in Duisburg flew at half mast on Monday as investigators probed allegations over lax safety measures at a techno festival where 19 people died.
The death toll from a stampede at a Love Parade techno music festival in Germany rose to 19 on Sunday and police pursued an investigation.
A stampede killed 18 people after mass panic broke out in a tunnel at a "Love Parade" techno music festival in Germany on Saturday.