Andy owns a warehouse. He made a contract with Bernie to repair the roof of the warehouse. They agree a total price of 20,000. 5,000 will be paid in advance and 15,000 is payable on completion of the work. After they make the contract, a group of young people break in and set fire to the warehouse, and it is completely destroyed. At the time of the fire, Bernie had completed half of the work and had incurred staff costs of 2,000 and expenditure on materials of 3,000. Advise Andy on his rights and liabilities to Bernie