Why did the worker injure himself?
Because he fell from a ladder
Why did he fall from a ladder?
Because he was not holding onto the ladder and overbalanced backwards
Why was he not holding onto the ladder?
Because he was using both hands to remove a large section of guttering
Why was he using both hands to remove guttering?
Because the system of work for gutter replacement was flawed so it was not possible for the worker to maintain three points of contact with the ladder
Why was there a flawed system of work in place?
Because the job had not been properly planned in advance