please answer using the appropriate law of tort. "occupiers liability". please use the law format

Harry inherits a large and dilapidated house from his mother. He moves in and decides to have substantial renovations carried out by Askew Alterations Ltd a local company that specializes in renovating old property. Whilst these alterations are in progress Harry decides to hold a party to welcome his new neighbours. Barney and his five-year-old daughter Clara attend. Clara becomes bored and wandered into a room marked 'Danger - do not enter' where she is injured. Barney while looking for Clara in the room turns on a light switch that has not been completely finished and suffered an electrical shock. Danny, who was aware that Harry's mother kept a good wine cellar goes down to the cellar intending to help himself to some wine, but slips on a cork on the steps and broke both his legs. Required: Advise Barney, Clara and Danny. (Total 20 marks)