Two twin brothers worked for the same employer in a construction site and were assigned to hack off an old brick wall with hand-held electric tools, both discussed and decided to knock off the lower parts of the wall and allow the wall to fall by gravity instead of from the top in order to save time and effort. The wall fell over the brothers, injured, who decided to launch separate claim against their employer on negligence. Formulate the brothers' separate claim and the Employer's defence.