May 28, 2014, at 10:30 pm. A sprinkler fired with a fire alarm at a mid-sized trading company. Immediately after the warning, everyone evacuated, except one or more. Only the head of the Brazilian project team was not visible. Eventually, the team leader Lee Sang Mi fell down on her office desk and was found dead. There was no trauma, and the estimated time of death was 9:55-10:30 pm. In recognition of her competence, the victim's team leader Lee Sang Mi gave an exaggeration in her sixth year of joining the company, and one year later, she was promoted to become the youngest team leader in the company. However, because of this, someone was envious. Is he/she the killer? (Source: namu.wiki)