When electricity is used the electrical terminals warm up and subsequently cool down. Over time this heat cycle can lossen the screws. If you look carefully you can see the black neutral chilling out in the back of the box. Get an Inspection and Test (EICR), done every 10 years to stop this happening. If you are a Landlord every 5 years or change of tenancy.
Having removed the connection block and cut the bad bit out of the neutral, it all became clear. Someone screwed through the cable in the wall and it went bang. Should have re-done live, neutral and earth but I guess he was in a hurry.
I couldn't understand what had happened here. The live has been joined together, the neutral has bare copper showing and the earth has disappeared
Someone thought if they wanted to add a socket they could run the cable over the carpet gripper under the carpet and up again. The cable was actually snagged on the gribber when we removed it. Should have been in mini trucking around the wall.
