Ten basic principles in safety, which were well explained by Heinrich's early works, can further lead to improvement in safety and reduction in the safety record. a) One of the principles states: "We can predict that certain sets of circumstances will produce severe injuries. These circumstances can be identified and controlled." Discuss with examples on circumstances that severe injuries are predictable. (13%) b) Another principle states: "The causes of unsafe behavior can be identified and classified. Specify which aspects lead to human error and explain why. (7%)