The judgment below is reversed and the case is remanded to Seoul High Court.

The grounds of appeal are examined.

1. The term "occupational accident" under Article 37 (1) of the Industrial Accident Compensation Insurance Act means the injury, disease, physical disability, or death of an employee who has caused the occupational accident while performing his/her duties, and therefore there is a causal relation between the occupational accident and the disaster.

The causal relationship is proved by the assertion, but it is not necessarily required to be proved by medical or natural science, and if there is a proximate causal relation from the normative point of view, it should be viewed that there is such proof.

Therefore, in a case where a worker dies due to a suicide, a proximate causal relation can be acknowledged between his/her duties and death when it can be inferred that the disease was caused or aggravated due to the occurrence of a disease due to his/her duties or occupational stress overlaps with the main cause of the disease, and that such disease was caused by lack of normal perception ability, choice ability, mental suppression ability, or considerable decrease in the ability to expect reasonable judgment.

In addition, in order to recognize such proximate causal relationship, comprehensive consideration should be given to the degree of the disease or aftermath of the person who committed the suicide, general symptoms of the disease, the period of medical care, the possibility of recovery, age, physical and psychological circumstances, the surrounding circumstances where the person committed the suicide was committed, and the circumstances leading to the suicide.

(see, e.g., Supreme Court Decision 2011Du14692, Oct. 30, 2014). Although an individual vulnerability, such as the resistant nature of the deceased, had an impact on the resolution of suicide.

It is not different for the reason that the deceased did not reach the symptoms of mental illness, such as a sense, loss, or over-injury immediately before the suicide.

(See Supreme Court Decision 2016Du58840 Decided May 31, 2017). (See Supreme Court Decision 2016Du58840, May 31, 2017).