Steve Kelly, of the GMB union, said: "When the pipes are laid, they have to be supported properly underneath, especially where they join.
"But it doesn't appear as if this happened and the pipes have dropped, causing them to become buckled.
"Apparently they are now going to have to dig up the pipes and repair them but that is a process that is going to take months. It's just one disaster after another."
Will this stadium be safe full stop?